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Yang JE, Mitchell JM, Bingman CA, Mosher DF, Wright ER. In situ crystalline structure of the human eosinophil major basic protein-1. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.10.09.617336. [PMID: 39416224 PMCID: PMC11483036 DOI: 10.1101/2024.10.09.617336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 10/19/2024]
Abstract
Eosinophils are white blood cells that participate in innate immune responses and have an essential role in the pathogenesis of inflammatory and neoplastic disorders. Upon activation, eosinophils release cytotoxic proteins such as major basic protein-1 (MBP-1) from cytoplasmic secretory granules (SGr) wherein MBP-1 is stored as nanocrystals. How the MBP-1 nanocrystalline core is formed, stabilized, and subsequently mobilized remains unknown. Here, we report the in-situ structure of crystalline MBP-1 within SGrs of human eosinophils. The structure reveals a mechanism for intragranular crystal packing and stabilization of MBP-1 via a structurally conserved loop region that is associated with calcium-dependent carbohydrate binding in other C-type lectin (CTL) proteins. Single-cell and single-SGr profiling correlating real-space three-dimensional information from cellular montage cryo-electron tomography (cryo-ET) and microcrystal electron diffraction (MicroED) data obtained from non-activated and IL33-activated eosinophils revealed activation-dependent crystal expansion and extrusion of expanded crystals from SGr. These results suggest that MBP-1 crystals play a dynamic role in the release of SGr contents. Collectively, this research demonstrates the importance of in-situ macromolecular structure determination.
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2
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Wu S, Cai B, Wang T, Cao Z, Peng H, Liu H. Eosinophil extracellular traps in respiratory ailment: Pathogenic mechanisms and clinical translation. World J Otorhinolaryngol Head Neck Surg 2024; 10:213-224. [PMID: 39233861 PMCID: PMC11369806 DOI: 10.1002/wjo2.138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 08/07/2023] [Accepted: 08/10/2023] [Indexed: 09/06/2024] Open
Abstract
Background Eosinophilic extracellular traps (EETs) are reticular complexes comprising deoxyribonucleic-Acid (DNA) fibers and granule proteins. Aims EETs play a crucial role in antimicrobial host responses and are pathogenic when overproduced or under degraded. EETs created by eosinophils appear to enable vital immune responses against extra-cellular pathogens, nevertheless, trap overproduction is evident in pathology. Materials & Methods As considerably research is performed, new data affirmed that EETs can alter the outcome of respiratory ailment. Results We probe into the disclosure and specificity of EETs produced in reaction to various stimuli and propose a role for those frameworks in ailment pathogenesis and the establishment of chronic, unresolved inflammation. Discussion Whether EETs can be used as a prospective brand-new target for the diagnosis, treatment and prognosis of respiratory ailments is a scientific theme worth studying. Conclusion We probe into the disclosure and specificity of EETs produced in reaction to various stimuli and propose a role for those frameworks in ailment pathogenesis and the establishment of chronic, unresolved inflammation.
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Affiliation(s)
- Shun‐Yu Wu
- Department of OtolaryngologyThe Second Affiliated Hospital of the Naval Military Medical University (Shanghai Changzheng Hospital)ShanghaiChina
| | - Bo‐Yu Cai
- Department of OtolaryngologyThe Second Affiliated Hospital of the Naval Military Medical University (Shanghai Changzheng Hospital)ShanghaiChina
| | - Tian‐Yu Wang
- Department of OtolaryngologyThe Second Affiliated Hospital of the Naval Military Medical University (Shanghai Changzheng Hospital)ShanghaiChina
| | - Zhi‐Wen Cao
- Department of OtolaryngologyThe Second Affiliated Hospital of the Naval Military Medical University (Shanghai Changzheng Hospital)ShanghaiChina
| | - Hu Peng
- Department of OtolaryngologyThe Second Affiliated Hospital of the Naval Military Medical University (Shanghai Changzheng Hospital)ShanghaiChina
| | - Huan‐Hai Liu
- Department of OtolaryngologyThe Second Affiliated Hospital of the Naval Military Medical University (Shanghai Changzheng Hospital)ShanghaiChina
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3
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Melo RCN, Silva TP. Eosinophil activation during immune responses: an ultrastructural view with an emphasis on viral diseases. J Leukoc Biol 2024; 116:321-334. [PMID: 38466831 DOI: 10.1093/jleuko/qiae058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 02/17/2024] [Accepted: 02/21/2024] [Indexed: 03/13/2024] Open
Abstract
Eosinophils are cells of the innate immune system that orchestrate complex inflammatory responses. The study of the cell biology of eosinophils, particularly associated with cell activation, is of great interest to understand their immune responses. From a morphological perspective, activated eosinophils show ultrastructural signatures that have provided critical insights into the comprehension of their functional capabilities. Application of conventional transmission electron microscopy in combination with quantitative assessments (quantitative transmission electron microscopy), molecular imaging (immunoEM), and 3-dimensional electron tomography have generated important insights into mechanisms of eosinophil activation. This review explores a multitude of ultrastructural events taking place in eosinophils activated in vitro and in vivo as key players in allergic and inflammatory diseases, with an emphasis on viral infections. Recent progress in our understanding of biological processes underlying eosinophil activation, including in vivo mitochondrial remodeling, is discussed, and it can bring new thinking to the field.
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Affiliation(s)
- Rossana C N Melo
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora (UFJF), Rua José Lourenço Kelmer, campus, Juiz de Fora, MG, 36036-900, Brazil
| | - Thiago P Silva
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora (UFJF), Rua José Lourenço Kelmer, campus, Juiz de Fora, MG, 36036-900, Brazil
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4
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Neves VH, Palazzi C, Malta KK, Bonjour K, Kneip F, Dias FF, Neves JS, Weller PF, Melo RCN. Extracellular sombrero vesicles are hallmarks of eosinophilic cytolytic degranulation in tissue sites of human diseases. J Leukoc Biol 2024; 116:398-408. [PMID: 38527801 PMCID: PMC11271979 DOI: 10.1093/jleuko/qiae079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 03/04/2024] [Accepted: 03/01/2024] [Indexed: 03/27/2024] Open
Abstract
Eosinophil sombrero vesicles are large tubular carriers resident in the cytoplasm of human eosinophils, identifiable by transmission electron microscopy, and important for immune mediator transport. Increased formation of sombrero vesicles occurs in activated eosinophils in vitro and in vivo. In tissue sites of eosinophilic cytolytic inflammation, extracellular eosinophil sombrero vesicles are noted, but their frequency and significance in eosinophil-associated diseases remain unclear. Here, we performed comprehensive quantitative transmission electron microscopy analyses and electron tomography to investigate the numbers, density, integrity, and 3-dimensional structure of eosinophil sombrero vesicles in different biopsy tissues from 5 prototypic eosinophil-associated diseases (eosinophilic chronic rhinosinusitis/nasal sinuses, ulcerative colitis/intestines, hypereosinophilic syndrome/skin, dermatitis/skin, and schistosomiasis/rectum). The morphology of extracellular eosinophil sombrero vesicles was also compared with that of cytoplasmic eosinophil sombrero vesicles, isolated by subcellular fractionation from peripheral blood eosinophils. We demonstrated that (i) eosinophil cytolysis, releasing intact sombrero vesicles and membrane-bound granules, is a consistent event in all eosinophil-associated diseases; (ii) eosinophil sombrero vesicles persist intact even after complete disintegration of all cell organelles, except granules (late cytolysis); (iii) the eosinophil sombrero vesicle population, composed of elongated, curved, and typical sombreros, and the eosinophil sombrero vesicle 3-dimensional architecture, diameter, and density remain unchanged in the extracellular matrix; (iv) free eosinophil sombrero vesicles closely associate with extracellular granules; and (v) free eosinophil sombrero vesicles also associate with externalized chromatin during eosinophil ETosis. Remarkably, eosinophil sombrero vesicles appeared on the surface of other cells, such as plasma cells. Thus, eosinophil cytolysis/ETosis can secrete intact sombrero vesicles, alongside granules, in inflamed tissues of eosinophil-associated diseases, potentially serving as propagators of eosinophil immune responses after cell death.
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Affiliation(s)
- Vitor H Neves
- Laboratory of Cellular Biology, Department of Biology, ICB, Federal University of Juiz de Fora, UFJF, Rua José Lourenço Kelmer, Juiz de Fora, MG 36036-900, Brazil
| | - Cinthia Palazzi
- Laboratory of Cellular Biology, Department of Biology, ICB, Federal University of Juiz de Fora, UFJF, Rua José Lourenço Kelmer, Juiz de Fora, MG 36036-900, Brazil
| | - Kássia K Malta
- Laboratory of Cellular Biology, Department of Biology, ICB, Federal University of Juiz de Fora, UFJF, Rua José Lourenço Kelmer, Juiz de Fora, MG 36036-900, Brazil
| | - Kennedy Bonjour
- Laboratory of Cellular Biology, Department of Biology, ICB, Federal University of Juiz de Fora, UFJF, Rua José Lourenço Kelmer, Juiz de Fora, MG 36036-900, Brazil
- Unity of Biochemistry Membrane and Transport, Department of Cellular Biology and Infection, Institut Pasteur, 75724 Paris Cedex 15, Paris, France
| | - Felipe Kneip
- Laboratory of Cellular Biology, Department of Biology, ICB, Federal University of Juiz de Fora, UFJF, Rua José Lourenço Kelmer, Juiz de Fora, MG 36036-900, Brazil
| | - Felipe F Dias
- Laboratory of Cellular Biology, Department of Biological Sciences, State University of Minas Gerais, UEMG, Avenida São Paulo 3996, Campus Ibirité, MG 32400-000, Brazil
| | - Josiane S Neves
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, UFRJ, Avenida Carlos Chagas Filho 373, Rio de Janeiro, RJ 21941-971, Brazil
| | - Peter F Weller
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, CLS 943, Boston, MA 02215, United States
| | - Rossana C N Melo
- Laboratory of Cellular Biology, Department of Biology, ICB, Federal University of Juiz de Fora, UFJF, Rua José Lourenço Kelmer, Juiz de Fora, MG 36036-900, Brazil
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5
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Pavathuparambil Abdul Manaph N, Ltaief SM, Nour-Eldine W, Ponraj J, Agcaoili J, Mansour S, Al-Shammari AR. An optimized protocol for the preparation of blood immune cells for transmission electron microscopy. Micron 2023; 173:103517. [PMID: 37556900 DOI: 10.1016/j.micron.2023.103517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 07/17/2023] [Accepted: 07/17/2023] [Indexed: 08/11/2023]
Abstract
Transmission electron microscopy (TEM) is a powerful technique that enables visualization of structural details inside cells. Prior to TEM imaging, biological samples must undergo several preparation steps that are optimized according to the sample type. Currently, there are limited protocols for the preparation of blood samples for TEM imaging. Here, we provide a detailed step-by-step method for preparing blood samples for TEM imaging. This protocol enables robust visualization of the ultrastructures of blood immune cells. In addition, we describe the typical cellular features that can be used to distinguish between different immune cells in the blood, such as neutrophils, eosinophils, monocytes, and lymphocytes. This protocol is useful for studying ultrastructural changes in blood immune cells under various physiological and disease conditions.
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Affiliation(s)
| | - Samia M Ltaief
- Neurological Disorders Research Center, Qatar Biomedical Research Institute, Hamad Bin Khalifa University, Qatar Foundation, Doha, Qatar
| | - Wared Nour-Eldine
- Neurological Disorders Research Center, Qatar Biomedical Research Institute, Hamad Bin Khalifa University, Qatar Foundation, Doha, Qatar
| | | | - John Agcaoili
- Core Labs, Hamad Bin Khalifa University, Qatar Foundation, Doha, Qatar
| | - Said Mansour
- Core Labs, Hamad Bin Khalifa University, Qatar Foundation, Doha, Qatar
| | - Abeer R Al-Shammari
- Neurological Disorders Research Center, Qatar Biomedical Research Institute, Hamad Bin Khalifa University, Qatar Foundation, Doha, Qatar.
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6
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Bonjour K, Palazzi C, Silva TP, Malta KK, Neves VH, Oliveira-Barros EG, Neves I, Kersten VA, Fortuna BT, Samarasinghe AE, Weller PF, Bandeira-Melo C, Melo RCN. Mitochondrial Population in Mouse Eosinophils: Ultrastructural Dynamics in Cell Differentiation and Inflammatory Diseases. Front Cell Dev Biol 2022; 10:836755. [PMID: 35386204 PMCID: PMC8979069 DOI: 10.3389/fcell.2022.836755] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 02/25/2022] [Indexed: 12/20/2022] Open
Abstract
Mitochondria are multifunctional organelles of which ultrastructure is tightly linked to cell physiology. Accumulating evidence shows that mitochondrial remodeling has an impact on immune responses, but our current understanding of the mitochondrial architecture, interactions, and morphological changes in immune cells, mainly in eosinophils, is still poorly known. Here, we applied transmission electron microscopy (TEM), single-cell imaging analysis, and electron tomography, a technique that provides three-dimensional (3D) views at high resolution, to investigate mitochondrial dynamics in mouse eosinophils developing in cultures as well as in the context of inflammatory diseases characterized by recruitment and activation of these cells (mouse models of asthma, H1N1 influenza A virus (IAV) infection, and schistosomiasis mansoni). First, quantitative analyses showed that the mitochondrial area decrease 70% during eosinophil development (from undifferentiated precursor cells to mature eosinophils). Mitophagy, a consistent process revealed by TEM in immature but not in mature eosinophils, is likely operating in mitochondrial clearance during eosinophilopoiesis. Events of mitochondria interaction (inter-organelle membrane contacts) were also detected and quantitated within developing eosinophils and included mitochondria-endoplasmic reticulum, mitochondria-mitochondria, and mitochondria-secretory granules, all of them significantly higher in numbers in immature compared to mature cells. Moreover, single-mitochondrion analyses revealed that as the eosinophil matures, mitochondria cristae significantly increase in number and reshape to lamellar morphology. Eosinophils did not change (asthma) or reduced (IAV and Schistosoma infections) their mitochondrial mass in response to inflammatory diseases. However, asthma and schistosomiasis, but not IAV infection, induced amplification of both cristae numbers and volume in individual mitochondria. Mitochondrial cristae remodeling occurred in all inflammatory conditions with the proportions of mitochondria containing only lamellar or tubular, or mixed cristae (an ultrastructural aspect seen just in tissue eosinophils) depending on the tissue/disease microenvironment. The ability of mitochondria to interact with granules, mainly mobilized ones, was remarkably captured by TEM in eosinophils participating in all inflammatory diseases. Altogether, we demonstrate that the processes of eosinophilopoiesis and inflammation-induced activation interfere with the mitochondrial dynamics within mouse eosinophils leading to cristae remodeling and inter-organelle contacts. The understanding of how mitochondrial dynamics contribute to eosinophil immune functions is an open interesting field to be explored.
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Affiliation(s)
- Kennedy Bonjour
- Laboratory of Cellular Biology, Department of Biology, ICB, Federal University of Juiz de Fora, Rua José Lourenço Kelmer, Juiz de Fora, Brazil
| | - Cinthia Palazzi
- Laboratory of Cellular Biology, Department of Biology, ICB, Federal University of Juiz de Fora, Rua José Lourenço Kelmer, Juiz de Fora, Brazil
| | - Thiago P Silva
- Laboratory of Cellular Biology, Department of Biology, ICB, Federal University of Juiz de Fora, Rua José Lourenço Kelmer, Juiz de Fora, Brazil
| | - Kássia K Malta
- Laboratory of Cellular Biology, Department of Biology, ICB, Federal University of Juiz de Fora, Rua José Lourenço Kelmer, Juiz de Fora, Brazil
| | - Vitor H Neves
- Laboratory of Cellular Biology, Department of Biology, ICB, Federal University of Juiz de Fora, Rua José Lourenço Kelmer, Juiz de Fora, Brazil
| | - Eliane G Oliveira-Barros
- Laboratory of Cellular Biology, Department of Biology, ICB, Federal University of Juiz de Fora, Rua José Lourenço Kelmer, Juiz de Fora, Brazil
| | - Igor Neves
- Laboratory of Cellular Biology, Department of Biology, ICB, Federal University of Juiz de Fora, Rua José Lourenço Kelmer, Juiz de Fora, Brazil
| | - Victor A Kersten
- Laboratory of Inflammation, Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Bruno T Fortuna
- Laboratory of Cellular Biology, Department of Biology, ICB, Federal University of Juiz de Fora, Rua José Lourenço Kelmer, Juiz de Fora, Brazil
| | - Amali E Samarasinghe
- Division of Pulmonology, Allergy-Immunology and Sleep, Department of Pediatrics, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, United States
| | - Peter F Weller
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States
| | - Christianne Bandeira-Melo
- Laboratory of Inflammation, Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Rossana C N Melo
- Laboratory of Cellular Biology, Department of Biology, ICB, Federal University of Juiz de Fora, Rua José Lourenço Kelmer, Juiz de Fora, Brazil.,Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States
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7
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Rodrigo-Muñoz JM, Gil-Martínez M, Sastre B, del Pozo V. Emerging Evidence for Pleiotropism of Eosinophils. Int J Mol Sci 2021; 22:ijms22137075. [PMID: 34209213 PMCID: PMC8269185 DOI: 10.3390/ijms22137075] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 06/25/2021] [Accepted: 06/27/2021] [Indexed: 02/08/2023] Open
Abstract
Eosinophils are complex granulocytes with the capacity to react upon diverse stimuli due to their numerous and variable surface receptors, which allows them to respond in very different manners. Traditionally believed to be only part of parasitic and allergic/asthmatic immune responses, as scientific studies arise, the paradigm about these cells is continuously changing, adding layers of complexity to their roles in homeostasis and disease. Developing principally in the bone marrow by the action of IL-5 and granulocyte macrophage colony-stimulating factor GM-CSF, eosinophils migrate from the blood to very different organs, performing multiple functions in tissue homeostasis as in the gastrointestinal tract, thymus, uterus, mammary glands, liver, and skeletal muscle. In organs such as the lungs and gastrointestinal tract, eosinophils are able to act as immune regulatory cells and also to perform direct actions against parasites, and bacteria, where novel mechanisms of immune defense as extracellular DNA traps are key factors. Besides, eosinophils, are of importance in an effective response against viral pathogens by their nuclease enzymatic activity and have been lately described as involved in severe acute respiratory syndrome coronavirus SARS-CoV-2 immunity. The pleiotropic role of eosinophils is sustained because eosinophils can be also detrimental to human physiology, for example, in diseases like allergies, asthma, and eosinophilic esophagitis, where exosomes can be significant pathophysiologic units. These eosinophilic pathologies, require specific treatments by eosinophils control, such as new monoclonal antibodies like mepolizumab, reslizumab, and benralizumab. In this review, we describe the roles of eosinophils as effectors and regulatory cells and their involvement in pathological disorders and treatment.
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Affiliation(s)
- José M. Rodrigo-Muñoz
- Immunoallergy Laboratory, Immunology Department, Instituto de Investigación Sanitaria Fundación Jiménez Díaz (IIS-FJD), Avenida Reyes Católicos, 28040 Madrid, Spain; (J.M.R.-M.); (M.G.-M.)
- CIBER de Enfermedades Respiratorias (CIBERES), Av. de Monforte de Lemos, 28029 Madrid, Spain
| | - Marta Gil-Martínez
- Immunoallergy Laboratory, Immunology Department, Instituto de Investigación Sanitaria Fundación Jiménez Díaz (IIS-FJD), Avenida Reyes Católicos, 28040 Madrid, Spain; (J.M.R.-M.); (M.G.-M.)
| | - Beatriz Sastre
- Immunoallergy Laboratory, Immunology Department, Instituto de Investigación Sanitaria Fundación Jiménez Díaz (IIS-FJD), Avenida Reyes Católicos, 28040 Madrid, Spain; (J.M.R.-M.); (M.G.-M.)
- CIBER de Enfermedades Respiratorias (CIBERES), Av. de Monforte de Lemos, 28029 Madrid, Spain
- Correspondence: (B.S.); (V.d.P.)
| | - Victoria del Pozo
- Immunoallergy Laboratory, Immunology Department, Instituto de Investigación Sanitaria Fundación Jiménez Díaz (IIS-FJD), Avenida Reyes Católicos, 28040 Madrid, Spain; (J.M.R.-M.); (M.G.-M.)
- CIBER de Enfermedades Respiratorias (CIBERES), Av. de Monforte de Lemos, 28029 Madrid, Spain
- Medicine Department, Universidad Autónoma de Madrid, 28029 Madrid, Spain
- Correspondence: (B.S.); (V.d.P.)
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8
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Fettrelet T, Gigon L, Karaulov A, Yousefi S, Simon HU. The Enigma of Eosinophil Degranulation. Int J Mol Sci 2021; 22:ijms22137091. [PMID: 34209362 PMCID: PMC8268949 DOI: 10.3390/ijms22137091] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 06/23/2021] [Accepted: 06/29/2021] [Indexed: 12/18/2022] Open
Abstract
Eosinophils are specialized white blood cells, which are involved in the pathology of diverse allergic and nonallergic inflammatory diseases. Eosinophils are traditionally known as cytotoxic effector cells but have been suggested to additionally play a role in immunomodulation and maintenance of homeostasis. The exact role of these granule-containing leukocytes in health and diseases is still a matter of debate. Degranulation is one of the key effector functions of eosinophils in response to diverse stimuli. The different degranulation patterns occurring in eosinophils (piecemeal degranulation, exocytosis and cytolysis) have been extensively studied in the last few years. However, the exact mechanism of the diverse degranulation types remains unknown and is still under investigation. In this review, we focus on recent findings and highlight the diversity of stimulation and methods used to evaluate eosinophil degranulation.
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Affiliation(s)
- Timothée Fettrelet
- Institute of Pharmacology, University of Bern, Inselspital, INO-F, CH-3010 Bern, Switzerland; (T.F.); (L.G.); (S.Y.)
- Department of Biochemistry, University of Lausanne, CH-1066 Epalinges, Switzerland
| | - Lea Gigon
- Institute of Pharmacology, University of Bern, Inselspital, INO-F, CH-3010 Bern, Switzerland; (T.F.); (L.G.); (S.Y.)
| | - Alexander Karaulov
- Department of Clinical Immunology and Allergology, Sechenov University, 119991 Moscow, Russia;
| | - Shida Yousefi
- Institute of Pharmacology, University of Bern, Inselspital, INO-F, CH-3010 Bern, Switzerland; (T.F.); (L.G.); (S.Y.)
| | - Hans-Uwe Simon
- Institute of Pharmacology, University of Bern, Inselspital, INO-F, CH-3010 Bern, Switzerland; (T.F.); (L.G.); (S.Y.)
- Department of Clinical Immunology and Allergology, Sechenov University, 119991 Moscow, Russia;
- Laboratory of Molecular Immunology, Institute of Fundamental Medicine and Biology, Kazan Federal University, 420012 Kazan, Russia
- Institute of Biochemistry, Medical School Brandenburg, D-16816 Neuruppin, Germany
- Correspondence: ; Tel.: +41-31-632-3281
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9
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Folci M, Ramponi G, Arcari I, Zumbo A, Brunetta E. Eosinophils as Major Player in Type 2 Inflammation: Autoimmunity and Beyond. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1347:197-219. [PMID: 34031864 DOI: 10.1007/5584_2021_640] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Abstract
Eosinophils are a subset of differentiated granulocytes which circulate in peripheral blood and home in several body tissues. Along with their traditional relevance in helminth immunity and allergy, eosinophils have been progressively attributed important roles in a number of homeostatic and pathologic situations. This review aims at summarizing available evidence about eosinophils functions in homeostasis, infections, allergic and autoimmune disorders, and solid and hematological cancers.Their structural and biological features have been described, along with their physiological behavior. This includes their chemokines, cytokines, granular contents, and extracellular traps. Besides, pathogenic- and eosinophilic-mediated disorders have also been addressed, with the aim of highlighting their role in Th2-driven inflammation. In allergy, eosinophils are implicated in the pathogenesis of atopic dermatitis, allergic rhinitis, and asthma. They are also fundamentally involved in autoimmune disorders such as eosinophilic esophagitis, eosinophilic gastroenteritis, acute and chronic eosinophilic pneumonia, and eosinophilic granulomatosis with polyangiitis. In infections, eosinophils are involved in protection not only from parasites but also from fungi, viruses, and bacteria. In solid cancers, local eosinophilic infiltration is variably associated with an improved or worsened prognosis, depending on the histotype. In hematologic neoplasms, eosinophilia can be the consequence of a dysregulated cytokine production or the result of mutations affecting the myeloid lineage.Recent experimental evidence was thoroughly reviewed, with findings which elicit a complex role for eosinophils, in a tight balance between host defense and tissue damage. Eventually, emerging evidence about eosinophils in COVID-19 infection was also discussed.
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Affiliation(s)
- Marco Folci
- Humanitas Clinical and Research Center - IRCCS, Milan, Italy. .,Department of Biomedical Sciences, Humanitas University, Milan, Italy.
| | - Giacomo Ramponi
- Humanitas Clinical and Research Center - IRCCS, Milan, Italy
| | - Ivan Arcari
- Humanitas Clinical and Research Center - IRCCS, Milan, Italy
| | - Aurora Zumbo
- Humanitas Clinical and Research Center - IRCCS, Milan, Italy
| | - Enrico Brunetta
- Humanitas Clinical and Research Center - IRCCS, Milan, Italy.,Department of Biomedical Sciences, Humanitas University, Milan, Italy
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10
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Germic N, Hosseini A, Yousefi S, Karaulov A, Simon HU. Regulation of eosinophil functions by autophagy. Semin Immunopathol 2021; 43:347-362. [PMID: 34019141 PMCID: PMC8241657 DOI: 10.1007/s00281-021-00860-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Accepted: 04/22/2021] [Indexed: 12/13/2022]
Abstract
Eosinophils are granule-containing leukocytes which develop in the bone marrow. For many years, eosinophils have been recognized as cytotoxic effector cells, but recent studies suggest that they perform additional immunomodulatory and homeostatic functions. Autophagy is a conserved intracellular process which preserves cellular homeostasis. Autophagy defects have been linked to the pathogenesis of many human disorders. Evidence for abnormal regulation of autophagy, including decreased or increased expression of autophagy-related (ATG) proteins, has been reported in several eosinophilic inflammatory disorders, such as Crohn's disease, bronchial asthma, eosinophilic esophagitis, and chronic rhinosinusitis. Despite the increasing extent of research using preclinical models of immune cell-specific autophagy deficiency, the physiological relevance of autophagic pathway in eosinophils has remained unknown until recently. Owing to the increasing evidence that eosinophils play a role in keeping organismal homeostasis, the regulation of eosinophil functions is of considerable interest. Here, we discuss the most recent advances on the role of autophagy in eosinophils, placing particular emphasis on insights obtained in mouse models of infections and malignant diseases in which autophagy has genetically dismantled in the eosinophil lineage. These studies pointed to the possibility that autophagy-deficient eosinophils exaggerate inflammation. Therefore, the pharmacological modulation of the autophagic pathway in these cells could be used for therapeutic interventions.
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Affiliation(s)
- Nina Germic
- Institute of Pharmacology, University of Bern, Inselspital, INO-F, 3010, Bern, Switzerland
| | - Aref Hosseini
- Institute of Pharmacology, University of Bern, Inselspital, INO-F, 3010, Bern, Switzerland
| | - Shida Yousefi
- Institute of Pharmacology, University of Bern, Inselspital, INO-F, 3010, Bern, Switzerland
| | - Alexander Karaulov
- Department of Clinical Immunology and Allergology, Sechenov University, 119991, Moscow, Russia
| | - Hans-Uwe Simon
- Institute of Pharmacology, University of Bern, Inselspital, INO-F, 3010, Bern, Switzerland. .,Department of Clinical Immunology and Allergology, Sechenov University, 119991, Moscow, Russia. .,Laboratory of Molecular Immunology, Institute of Fundamental Medicine and Biology, Kazan Federal University, 420012, Kazan, Russia.
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11
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Ménasché G, Longé C, Bratti M, Blank U. Cytoskeletal Transport, Reorganization, and Fusion Regulation in Mast Cell-Stimulus Secretion Coupling. Front Cell Dev Biol 2021; 9:652077. [PMID: 33796537 PMCID: PMC8007931 DOI: 10.3389/fcell.2021.652077] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 02/03/2021] [Indexed: 01/16/2023] Open
Abstract
Mast cells are well known for their role in allergies and many chronic inflammatory diseases. They release upon stimulation, e.g., via the IgE receptor, numerous bioactive compounds from cytoplasmic secretory granules. The regulation of granule secretion and its interaction with the cytoskeleton and transport mechanisms has only recently begun to be understood. These studies have provided new insight into the interaction between the secretory machinery and cytoskeletal elements in the regulation of the degranulation process. They suggest a tight coupling of these two systems, implying a series of specific signaling effectors and adaptor molecules. Here we review recent knowledge describing the signaling events regulating cytoskeletal reorganization and secretory granule transport machinery in conjunction with the membrane fusion machinery that occur during mast cell degranulation. The new insight into MC biology offers novel strategies to treat human allergic and inflammatory diseases targeting the late steps that affect harmful release from granular stores leaving regulatory cytokine secretion intact.
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Affiliation(s)
- Gaël Ménasché
- Laboratory of Molecular Basis of Altered Immune Homeostasis, Imagine Institute, INSERM UMR 1163, Université de Paris, Paris, France
| | - Cyril Longé
- Laboratory of Molecular Basis of Altered Immune Homeostasis, Imagine Institute, INSERM UMR 1163, Université de Paris, Paris, France
| | - Manuela Bratti
- Centre de Recherche sur l'Inflammation, INSERM UMR 1149, CNRS ERL8252, Faculté de Médecine site Bichat, Université de Paris, Paris, France.,Laboratoire d'Excellence Inflamex, Université de Paris, Paris, France
| | - Ulrich Blank
- Centre de Recherche sur l'Inflammation, INSERM UMR 1149, CNRS ERL8252, Faculté de Médecine site Bichat, Université de Paris, Paris, France.,Laboratoire d'Excellence Inflamex, Université de Paris, Paris, France
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12
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Masterson JC, Menard-Katcher C, Larsen LD, Furuta GT, Spencer LA. Heterogeneity of Intestinal Tissue Eosinophils: Potential Considerations for Next-Generation Eosinophil-Targeting Strategies. Cells 2021; 10:cells10020426. [PMID: 33671475 PMCID: PMC7922004 DOI: 10.3390/cells10020426] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 02/08/2021] [Accepted: 02/10/2021] [Indexed: 02/05/2023] Open
Abstract
Eosinophils are implicated in the pathophysiology of a spectrum of eosinophil-associated diseases, including gastrointestinal eosinophilic diseases (EGIDs). Biologics that target the IL-5 pathway and are intended to ablate eosinophils have proved beneficial in severe eosinophilic asthma and may offer promise in treating some endotypes of EGIDs. However, destructive effector functions of eosinophils are only one side of the coin; eosinophils also play important roles in immune and tissue homeostasis. A growing body of data suggest tissue eosinophils represent a plastic and heterogeneous population of functional sub-phenotypes, shaped by environmental (systemic and local) pressures, which may differentially impact disease outcomes. This may be particularly relevant to the GI tract, wherein the highest density of eosinophils reside in the steady state, resident immune cells are exposed to an especially broad range of external and internal environmental pressures, and greater eosinophil longevity may uniquely enrich for co-expression of eosinophil sub-phenotypes. Here we review the growing evidence for functional sub-phenotypes of intestinal tissue eosinophils, with emphasis on the multifactorial pressures that shape and diversify eosinophil identity and potential targets to inform next-generation eosinophil-targeting strategies designed to restrain inflammatory eosinophil functions while sustaining homeostatic roles.
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Affiliation(s)
- Joanne C. Masterson
- Gastrointestinal Eosinophilic Diseases Program, Department of Pediatrics, Digestive Health Institute, Children’s Hospital Colorado, University of Colorado School of Medicine, Aurora, CO 80045, USA; (J.C.M.); (C.M.-K.); (L.D.L.); (G.T.F.)
- GI and Liver Innate Immune Program, Department of Medicine, University of Colorado School of Medicine, Aurora, CO 80045, USA
- Allergy, Inflammation & Remodeling Research Laboratory, Kathleen Lonsdale Institute for Human Health Research, Department of Biology, Maynooth University, Maynooth, County Kildare, Ireland
| | - Calies Menard-Katcher
- Gastrointestinal Eosinophilic Diseases Program, Department of Pediatrics, Digestive Health Institute, Children’s Hospital Colorado, University of Colorado School of Medicine, Aurora, CO 80045, USA; (J.C.M.); (C.M.-K.); (L.D.L.); (G.T.F.)
| | - Leigha D. Larsen
- Gastrointestinal Eosinophilic Diseases Program, Department of Pediatrics, Digestive Health Institute, Children’s Hospital Colorado, University of Colorado School of Medicine, Aurora, CO 80045, USA; (J.C.M.); (C.M.-K.); (L.D.L.); (G.T.F.)
| | - Glenn T. Furuta
- Gastrointestinal Eosinophilic Diseases Program, Department of Pediatrics, Digestive Health Institute, Children’s Hospital Colorado, University of Colorado School of Medicine, Aurora, CO 80045, USA; (J.C.M.); (C.M.-K.); (L.D.L.); (G.T.F.)
- GI and Liver Innate Immune Program, Department of Medicine, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Lisa A. Spencer
- Gastrointestinal Eosinophilic Diseases Program, Department of Pediatrics, Digestive Health Institute, Children’s Hospital Colorado, University of Colorado School of Medicine, Aurora, CO 80045, USA; (J.C.M.); (C.M.-K.); (L.D.L.); (G.T.F.)
- GI and Liver Innate Immune Program, Department of Medicine, University of Colorado School of Medicine, Aurora, CO 80045, USA
- Correspondence: ; Tel.: +1-303-724-3277
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13
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Germic N, Fettrelet T, Stojkov D, Hosseini A, Horn MP, Karaulov A, Simon D, Yousefi S, Simon HU. The Release Kinetics of Eosinophil Peroxidase and Mitochondrial DNA Is Different in Association with Eosinophil Extracellular Trap Formation. Cells 2021; 10:cells10020306. [PMID: 33546138 PMCID: PMC7913244 DOI: 10.3390/cells10020306] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 01/29/2021] [Accepted: 01/30/2021] [Indexed: 01/03/2023] Open
Abstract
Eosinophils are a subset of granulocytes characterized by a high abundance of specific granules in their cytoplasm. To act as effector cells, eosinophils degranulate and form eosinophil extracellular traps (EETs), which contain double-stranded DNA (dsDNA) co-localized with granule proteins. The exact molecular mechanism of EET formation remains unknown. Although the term “EET release” has been used in scientific reports, it is unclear whether EETs are pre-formed in eosinophils and subsequently released. Moreover, although eosinophil degranulation has been extensively studied, a precise time-course of granule protein release has not been reported until now. In this study, we investigated the time-dependent release of eosinophil peroxidase (EPX) and mitochondrial DNA (mtDNA) following activation of both human and mouse eosinophils. Unexpectedly, maximal degranulation was already observed within 1 min with no further change upon complement factor 5 (C5a) stimulation of interleukin-5 (IL-5) or granulocyte/macrophage colony-stimulating factor (GM-CSF)-primed eosinophils. In contrast, bulk mtDNA release in the same eosinophil populations occurred much slower and reached maximal levels between 30 and 60 min. Although no single-cell analyses have been performed, these data suggest that the molecular pathways leading to degranulation and mtDNA release are at least partially different. Moreover, based on these data, it is likely that the association between the mtDNA scaffold and granule proteins in the process of EET formation occurs in the extracellular space.
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Affiliation(s)
- Nina Germic
- Institute of Pharmacology, University of Bern, Inselspital, INO-F, CH-3010 Bern, Switzerland; (N.G.); (T.F.); (D.S.); (A.H.); (S.Y.)
| | - Timothée Fettrelet
- Institute of Pharmacology, University of Bern, Inselspital, INO-F, CH-3010 Bern, Switzerland; (N.G.); (T.F.); (D.S.); (A.H.); (S.Y.)
- Department of Biochemistry, University of Lausanne, CH-1066 Epalinges, Switzerland
| | - Darko Stojkov
- Institute of Pharmacology, University of Bern, Inselspital, INO-F, CH-3010 Bern, Switzerland; (N.G.); (T.F.); (D.S.); (A.H.); (S.Y.)
| | - Aref Hosseini
- Institute of Pharmacology, University of Bern, Inselspital, INO-F, CH-3010 Bern, Switzerland; (N.G.); (T.F.); (D.S.); (A.H.); (S.Y.)
| | - Michael P. Horn
- Department of Clinical Chemistry, Inselspital, Bern University Hospital, University of Bern, CH-3010 Bern, Switzerland;
| | - Alexander Karaulov
- Department of Clinical Immunology and Allergology, Sechenov University, 119991 Moscow, Russia;
| | - Dagmar Simon
- Department of Dermatology, Inselspital, Bern University Hospital, University of Bern, CH-3010 Bern, Switzerland;
| | - Shida Yousefi
- Institute of Pharmacology, University of Bern, Inselspital, INO-F, CH-3010 Bern, Switzerland; (N.G.); (T.F.); (D.S.); (A.H.); (S.Y.)
| | - Hans-Uwe Simon
- Institute of Pharmacology, University of Bern, Inselspital, INO-F, CH-3010 Bern, Switzerland; (N.G.); (T.F.); (D.S.); (A.H.); (S.Y.)
- Department of Clinical Immunology and Allergology, Sechenov University, 119991 Moscow, Russia;
- Laboratory of Molecular Immunology, Institute of Fundamental Medicine and Biology, Kazan Federal University, 420012 Kazan, Russia
- Correspondence: ; Tel.: +41-31-632-3281
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14
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Cañas JA, Rodrigo-Muñoz JM, Gil-Martínez M, Sastre B, del Pozo V. Exosomes: A Key Piece in Asthmatic Inflammation. Int J Mol Sci 2021; 22:963. [PMID: 33478047 PMCID: PMC7835850 DOI: 10.3390/ijms22020963] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/13/2021] [Accepted: 01/18/2021] [Indexed: 02/07/2023] Open
Abstract
Asthma is a chronic disease of the airways that has an important inflammatory component. Multiple cells are implicated in asthma pathogenesis (lymphocytes, eosinophils, mast cells, basophils, neutrophils), releasing a wide variety of cytokines. These cells can exert their inflammatory functions throughout extracellular vesicles (EVs), which are small vesicles released by donor cells into the extracellular microenvironment that can be taken up by recipient cells. Depending on their size, EVs can be classified as microvesicles, exosomes, or apoptotic bodies. EVs are heterogeneous spherical structures secreted by almost all cell types. One of their main functions is to act as transporters of a wide range of molecules, such as proteins, lipids, and microRNAs (miRNAs), which are single-stranded RNAs of approximately 22 nucleotides in length. Therefore, exosomes could influence several physiological and pathological processes, including those involved in asthma. They can be detected in multiple cell types and biofluids, providing a wealth of information about the processes that take account in a pathological scenario. This review thus summarizes the most recent insights concerning the role of exosomes from different sources (several cell populations and biofluids) in one of the most prevalent respiratory diseases, asthma.
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Affiliation(s)
- José A. Cañas
- Immunoallergy Laboratory, Immunology Department, Instituto de Investigación Sanitaria Fundación Jiménez Díaz (IIS-FJD), Avenida Reyes Católicos, 2, 28040 Madrid, Spain; (J.A.C.); (J.M.R.-M.); (M.G.-M.)
- CIBER de Enfermedades Respiratorias (CIBERES), Av. de Monforte de Lemos, 3-5, 28029 Madrid, Spain
| | - José M. Rodrigo-Muñoz
- Immunoallergy Laboratory, Immunology Department, Instituto de Investigación Sanitaria Fundación Jiménez Díaz (IIS-FJD), Avenida Reyes Católicos, 2, 28040 Madrid, Spain; (J.A.C.); (J.M.R.-M.); (M.G.-M.)
- CIBER de Enfermedades Respiratorias (CIBERES), Av. de Monforte de Lemos, 3-5, 28029 Madrid, Spain
| | - Marta Gil-Martínez
- Immunoallergy Laboratory, Immunology Department, Instituto de Investigación Sanitaria Fundación Jiménez Díaz (IIS-FJD), Avenida Reyes Católicos, 2, 28040 Madrid, Spain; (J.A.C.); (J.M.R.-M.); (M.G.-M.)
| | - Beatriz Sastre
- Immunoallergy Laboratory, Immunology Department, Instituto de Investigación Sanitaria Fundación Jiménez Díaz (IIS-FJD), Avenida Reyes Católicos, 2, 28040 Madrid, Spain; (J.A.C.); (J.M.R.-M.); (M.G.-M.)
- CIBER de Enfermedades Respiratorias (CIBERES), Av. de Monforte de Lemos, 3-5, 28029 Madrid, Spain
| | - Victoria del Pozo
- Immunoallergy Laboratory, Immunology Department, Instituto de Investigación Sanitaria Fundación Jiménez Díaz (IIS-FJD), Avenida Reyes Católicos, 2, 28040 Madrid, Spain; (J.A.C.); (J.M.R.-M.); (M.G.-M.)
- CIBER de Enfermedades Respiratorias (CIBERES), Av. de Monforte de Lemos, 3-5, 28029 Madrid, Spain
- Faculty of Medicine, Universidad Autónoma de Madrid, 28029 Madrid, Spain
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15
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Abstract
The eosinophil is an enigmatic cell with a continuing ability to fascinate. A considerable history of research endeavor on eosinophil biology stretches from the present time back to the nineteenth century. Perhaps one of the most fascinating aspects of the eosinophil is how accumulating knowledge has changed the perception of its function from passive bystander, modulator of inflammation, to potent effector cell loaded with histotoxic substances through to more recent recognition that it can act as both a positive and negative regulator of complex events in both innate and adaptive immunity. This book consists of chapters written by experts in the field of eosinophil biology that provide comprehensive clearly written protocols for techniques designed to underpin research into the function of the eosinophil in health and disease.
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Affiliation(s)
- Paige Lacy
- Alberta Respiratory Centre (ARC) Research, Department of Medicine, University of Alberta, Edmonton, AB, Canada
| | - Helene F Rosenberg
- Inflammation Immunobiology Section, Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Garry M Walsh
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK.
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16
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Piasecka J, Thornton CA, Rees P, Summers HD. Diffusion Mapping of Eosinophil-Activation State. Cytometry A 2020; 97:253-258. [PMID: 31472007 PMCID: PMC7079009 DOI: 10.1002/cyto.a.23884] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 06/26/2019] [Accepted: 08/19/2019] [Indexed: 12/13/2022]
Abstract
Eosinophils are granular leukocytes that play a role in mediating inflammatory responses linked to infection and allergic disease. Their activation during an immune response triggers spatial reorganization and eventual cargo release from intracellular granules. Understanding this process is important in diagnosing eosinophilic disorders and in assessing treatment efficacy; however, current protocols are limited to simply quantifying the number of eosinophils within a blood sample. Given that high optical absorption and scattering by the granular structure of these cells lead to marked image features, the physical changes that occur during activation should be trackable using image analysis. Here, we present a study in which imaging flow cytometry is used to quantify eosinophil activation state, based on the extraction of 85 distinct spatial features from dark-field images formed by light scattered orthogonally to the illuminating beam. We apply diffusion mapping, a time inference method that orders cells on a trajectory based on similar image features. Analysis of exogenous cell activation using eotaxin and endogenous activation in donor samples with elevated eosinophil counts shows that cell position along the diffusion-path line correlates with activation level (99% confidence level). Thus, the diffusion mapping provides an activation metric for each cell. Assessment of activated and control populations using both this spatial image-based, activation score and the integrated side-scatter intensity shows an improved Fisher discriminant ratio rd = 0.7 for the multivariate technique compared with an rd = 0.47 for the traditional whole-cell scatter metric. © 2019 The Authors. Cytometry Part A published by Wiley Periodicals, Inc. on behalf of International Society for Advancement of Cytometry.
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Affiliation(s)
- Justyna Piasecka
- Swansea University Medical SchoolSwansea UniversitySwanseaSA2 8PPUK
| | | | - Paul Rees
- Systems and Process Engineering Centre, College of EngineeringSwansea UniversitySwanseaSA1 8ENUK
| | - Huw D. Summers
- Systems and Process Engineering Centre, College of EngineeringSwansea UniversitySwanseaSA1 8ENUK
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17
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Grozdanovic MM, Doyle CB, Liu L, Maybruck BT, Kwatia MA, Thiyagarajan N, Acharya KR, Ackerman SJ. Charcot-Leyden crystal protein/galectin-10 interacts with cationic ribonucleases and is required for eosinophil granulogenesis. J Allergy Clin Immunol 2020; 146:377-389.e10. [PMID: 31982451 DOI: 10.1016/j.jaci.2020.01.013] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 10/28/2019] [Accepted: 01/03/2020] [Indexed: 01/10/2023]
Abstract
BACKGROUND The human eosinophil Charcot-Leyden crystal (CLC) protein is a member of the Galectin superfamily and is also known as galectin-10 (Gal-10). CLC/Gal-10 forms the distinctive hexagonal bipyramidal crystals that are considered hallmarks of eosinophil participation in allergic responses and related inflammatory reactions; however, the glycan-containing ligands of CLC/Gal-10, its cellular function(s), and its role(s) in allergic diseases are unknown. OBJECTIVE We sought to determine the binding partners of CLC/Gal-10 and elucidate its role in eosinophil biology. METHODS Intracellular binding partners were determined by ligand blotting with CLC/Gal-10, followed by coimmunoprecipitation and coaffinity purifications. The role of CLC/Gal-10 in eosinophil function was determined by using enzyme activity assays, confocal microscopy, and short hairpin RNA knockout of CLC/Gal-10 expression in human CD34+ cord blood hematopoietic progenitors differentiated to eosinophils. RESULTS CLC/Gal-10 interacts with both human eosinophil granule cationic ribonucleases (RNases), namely, eosinophil-derived neurotoxin (RNS2) and eosinophil cationic protein (RNS3), and with murine eosinophil-associated RNases. The interaction is independent of glycosylation and is not inhibitory toward endoRNase activity. Activation of eosinophils with INF-γ induces the rapid colocalization of CLC/Gal-10 with eosinophil-derived neurotoxin/RNS2 and CD63. Short hairpin RNA knockdown of CLC/Gal-10 in human cord blood-derived CD34+ progenitor cells impairs eosinophil granulogenesis. CONCLUSIONS CLC/Gal-10 functions as a carrier for the sequestration and vesicular transport of the potent eosinophil granule cationic RNases during both differentiation and degranulation, enabling their intracellular packaging and extracellular functions in allergic inflammation.
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Affiliation(s)
- Milica M Grozdanovic
- Department of Biochemistry and Molecular Genetics, College of Medicine, University of Illinois at Chicago, Chicago, Ill
| | - Christine B Doyle
- Department of Biochemistry and Molecular Genetics, College of Medicine, University of Illinois at Chicago, Chicago, Ill
| | - Li Liu
- Department of Biochemistry and Molecular Genetics, College of Medicine, University of Illinois at Chicago, Chicago, Ill
| | - Brian T Maybruck
- Department of Biochemistry and Molecular Genetics, College of Medicine, University of Illinois at Chicago, Chicago, Ill
| | - Mark A Kwatia
- Department of Biochemistry and Molecular Genetics, College of Medicine, University of Illinois at Chicago, Chicago, Ill
| | - Nethaji Thiyagarajan
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - K Ravi Acharya
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Steven J Ackerman
- Department of Biochemistry and Molecular Genetics, College of Medicine, University of Illinois at Chicago, Chicago, Ill.
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18
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Trib1 regulates eosinophil lineage commitment and identity by restraining the neutrophil program. Blood 2019; 133:2413-2426. [PMID: 30917956 DOI: 10.1182/blood.2018872218] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 03/26/2019] [Indexed: 12/14/2022] Open
Abstract
Eosinophils and neutrophils are critical for host defense, yet gaps in understanding how granulocytes differentiate from hematopoietic stem cells (HSCs) into mature effectors remain. The pseudokinase tribbles homolog 1 (Trib1) is an important regulator of granulocytes; knockout mice lack eosinophils and have increased neutrophils. However, how Trib1 regulates cellular identity and function during eosinophilopoiesis is not understood. Trib1 expression markedly increases with eosinophil-lineage commitment in eosinophil progenitors (EoPs), downstream of the granulocyte/macrophage progenitor (GMP). Using hematopoietic- and eosinophil-lineage-specific Trib1 deletion, we found that Trib1 regulates both granulocyte precursor lineage commitment and mature eosinophil identity. Conditional Trib1 deletion in HSCs reduced the size of the EoP pool and increased neutrophils, whereas deletion following eosinophil lineage commitment blunted the decrease in EoPs without increasing neutrophils. In both modes of deletion, Trib1-deficient mice expanded a stable population of Ly6G+ eosinophils with neutrophilic characteristics and functions, and had increased CCAAT/enhancer binding protein α (C/EBPα) p42. Using an ex vivo differentiation assay, we found that interleukin 5 (IL-5) supports the generation of Ly6G+ eosinophils from Trib1-deficient cells, but is not sufficient to restore normal eosinophil differentiation and development. Furthermore, we demonstrated that Trib1 loss blunted eosinophil migration and altered chemokine receptor expression, both in vivo and ex vivo. Finally, we showed that Trib1 controls eosinophil identity by modulating C/EBPα. Together, our findings provide new insights into early events in myelopoiesis, whereby Trib1 functions at 2 distinct stages to guide eosinophil lineage commitment from the GMP and suppress the neutrophil program, promoting eosinophil terminal identity and maintaining lineage fidelity.
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19
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Shamri R, Young KM, Weller PF. Rho and Rac, but not ROCK, are required for secretion of human and mouse eosinophil-associated RNases. Clin Exp Allergy 2019; 49:190-198. [PMID: 30295352 PMCID: PMC6353669 DOI: 10.1111/cea.13292] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 09/13/2018] [Accepted: 10/03/2018] [Indexed: 01/21/2023]
Abstract
BACKGROUND Eosinophil-associated RNases (EARs) are stored preformed in eosinophil cytoplasmic secretory granules and have a key role in eosinophil effector functions in host defence and inflammatory disorders. However, the secretion mechanisms of EARs are poorly understood. OBJECTIVE Our study aimed to understand the involvement of cytoskeleton machinery in EAR secretion. METHODS Fresh human and mouse eosinophils were stimulated with CCL11, and the secretion of enzymatically active EARs was detected using an RNase activity assay. The involvement of cytoskeletal elements or microtubules was probed using specific inhibitors. RESULTS We found that dynamic polymerization of microtubules and cytoskeletal elements, such as Rho and Rac, is required for chemokine-mediated EAR secretion from human and mouse eosinophils. However, inhibition of ROCK (Rho-associated protein kinase) increased EAR secretion in human and mouse eosinophils even in the absence of chemokine stimulation, suggesting ROCK negatively regulates EAR secretion. CONCLUSIONS Collectively, these data suggest a cytoskeleton-dependent mechanism of EAR secretion from eosinophils, findings that are pertinent to host defence, allergy and other eosinophil-associated diseases.
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Affiliation(s)
- Revital Shamri
- Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel 91120
- Division of Allergy and Inflammation, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA 02215
| | - Kristen M. Young
- Division of Allergy and Inflammation, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA 02215
| | - Peter F. Weller
- Division of Allergy and Inflammation, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA 02215
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20
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21
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Carmo LAS, Bonjour K, Spencer LA, Weller PF, Melo RCN. Single-Cell Analyses of Human Eosinophils at High Resolution to Understand Compartmentalization and Vesicular Trafficking of Interferon-Gamma. Front Immunol 2018; 9:1542. [PMID: 30038615 PMCID: PMC6046373 DOI: 10.3389/fimmu.2018.01542] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 06/21/2018] [Indexed: 12/16/2022] Open
Abstract
Human eosinophils release numerous cytokines that are pre-synthesized and stored within their cytoplasmic-specific (secretory) granules. For example, high levels of interferon-gamma (IFN-γ) are constitutively expressed in these cells, but the intracellular compartments involved in the transport and release of this cytokine remain to be established. In this work, we used a single-cell approach to investigate the subcellular localization of IFN-γ in human eosinophils stimulated or not with tumor necrosis factor alpha (TNF-α) or CC-chemokine ligand 11 CCL11 (eotaxin-1), inflammatory mediators that induce eosinophil activation and secretion. A pre-embedding immunonanogold transmission electron microscopy (TEM) technique that combines optimal epitope preservation and access to membrane microdomains was applied to detect precise localization of IFN-γ in combination with computational quantitative analyses. In parallel, degranulation processes and formation of eosinophil sombrero vesicles (EoSVs), large transport carriers involved in the transport of granule-derived cytokines, were investigated. Quantitative TEM revealed that both CCL11 and TNF-α-activated eosinophils significantly increased the total number of EoSVs compared to the unstimulated group, indicating that this vesicular system is actively formed in response to cell activation. Ultrastructural immunolabeling identified a robust pool of IFN-γ on secretory granules in both unstimulated and stimulated cells. Moreover, EoSVs carrying IFN-γ were seen around or/and in contact with secretory granules and also distributed in the cytoplasm. Labeling was clearly associated with EoSV membranes. The total number of IFN-γ-positive EoSVs was significantly higher in stimulated compared to unstimulated cells, and these labeled vesicles had a differential distribution in the cytoplasm of activated cells, being significantly higher in the cell periphery compared with the inner cell, thus revealing intracellular IFN-γ mobilization for release. IFN-γ extracellular labeling was found at the cell surface, including on extracellular vesicles. Our results provide direct evidence that human eosinophils compartmentalize IFN-γ within secretory granules and identify, for the first time, a vesicular trafficking of IFN-γ associated with large transport carriers. This is important to understand how IFN-γ is trafficked and secreted during inflammatory responses.
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Affiliation(s)
- Lívia A S Carmo
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora, Juiz de Fora, Brazil
| | - Kennedy Bonjour
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora, Juiz de Fora, Brazil
| | - Lisa A Spencer
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States
| | - Peter F Weller
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States
| | - Rossana C N Melo
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora, Juiz de Fora, Brazil.,Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States
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22
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Melo RCN, Weller PF. Contemporary understanding of the secretory granules in human eosinophils. J Leukoc Biol 2018; 104:85-93. [PMID: 29749658 DOI: 10.1002/jlb.3mr1217-476r] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 02/14/2018] [Accepted: 02/16/2018] [Indexed: 12/12/2022] Open
Abstract
Eosinophil secretory (specific) granules have a unique morphology and are both a morphologic hallmark of eosinophils and fundamental to eosinophil-mediated responses. Eosinophil mediators with multiple functional activities are presynthesized and stored within these granules, poised for very rapid, stimulus-induced secretion. The structural organization and changes of eosinophil specific granules are revealing in demonstrating the complex and diverse secretory activities of this cell. Here, we review our current knowledge on the architecture, composition, and function of eosinophil specific granules as highly elaborated organelles able to produce vesiculotubular carriers and to interplay with the intracellular vesicular trafficking. We reconsider prior identifications of eosinophil cytoplasmic granules, including "primary," "secondary," "microgranules," and "small granules"; and consonant with advances, we provide a contemporary recognition that human eosinophils contain a single population of specific granules and their developmental precursors and derived secretory vesicles.
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Affiliation(s)
- Rossana C N Melo
- Laboratory of Cellular Biology, Department of Biology, ICB, Federal University of Juiz de Fora, UFJF, Rua José Lourenço Kelmer, Juiz de Fora, Brazil.,Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Peter F Weller
- Laboratory of Cellular Biology, Department of Biology, ICB, Federal University of Juiz de Fora, UFJF, Rua José Lourenço Kelmer, Juiz de Fora, Brazil
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Abstract
Eosinophils are a prominent cell type in particular host responses such as the response to helminth infection and allergic disease. Their effector functions have been attributed to their capacity to release cationic proteins stored in cytoplasmic granules by degranulation. However, eosinophils are now being recognized for more varied functions in previously underappreciated diverse tissue sites, based on the ability of eosinophils to release cytokines (often preformed) that mediate a broad range of activities into the local environment. In this Review, we consider evolving insights into the tissue distribution of eosinophils and their functional immunobiology, which enable eosinophils to secrete in a selective manner cytokines and other mediators that have diverse, 'non-effector' functions in health and disease.
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Affiliation(s)
- Peter F Weller
- Division of Allergy and Inflammation, Harvard Medical School, Beth Israel Deaconess Medical Center, CLS 943, 330 Brookline Avenue, Boston, Massachusetts 02215, USA
| | - Lisa A Spencer
- Division of Allergy and Inflammation, Harvard Medical School, Beth Israel Deaconess Medical Center, CLS 943, 330 Brookline Avenue, Boston, Massachusetts 02215, USA
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de Graauw E, Sitaru C, Horn M, Borradori L, Yousefi S, Simon HU, Simon D. Evidence for a role of eosinophils in blister formation in bullous pemphigoid. Allergy 2017; 72:1105-1113. [PMID: 28135772 DOI: 10.1111/all.13131] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/22/2017] [Indexed: 01/21/2023]
Abstract
BACKGROUND Bullous pemphigoid (BP) is an autoimmune bullous disease of the skin characterized by subepidermal blister formation due to tissue-bound and circulating autoantibodies to the hemidesmosomal antigens BP180 and BP230. Although eosinophils and their toxic mediators are found abundantly in BP lesions, their role in blister formation has remained unclear. OBJECTIVE To investigate the role of eosinophils in the pathogenesis of BP with a specific focus on blister formation and to define conditions inducing dermal-epidermal separation (DES). METHODS In an ex vivo human model of BP, normal human skin cryosections were incubated with purified human peripheral blood eosinophils with or without activation in the presence or absence of BP autoantibodies, brefeldin A, diphenyleneiodonium, DNase or blocking F(ab')2 fragments to CD16, CD18, CD32 and CD64. Dermal-epidermal separation was assessed by light microscopy studies and quantified using Fiji software. RESULTS Following activation with IL-5 and in the presence of BP autoantibodies, eosinophils induced separation along the dermal-epidermal junction of ex vivo skin. Dermal-epidermal separation was significantly reduced by blocking any of the following: Fcγ receptor binding (P = 0.048), eosinophil adhesion (P = 0.046), reactive oxygen species (ROS) production (P = 0.002), degranulation (P < 0.0001) or eosinophil extracellular trap (EET) formation (P = 0.048). CONCLUSIONS Our results provide evidence that IL-5-activated eosinophils directly contribute to BP blister formation in the presence of BP autoantibodies. Dermal-epidermal separation by IL-5-activated eosinophils depends on adhesion and Fcγ receptor activation, requires elevated ROS production and degranulation and involves EET formation. Thus, targeting eosinophils may be a promising therapeutic approach for BP.
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Affiliation(s)
- E. de Graauw
- Institute of Pharmacology; University of Bern; Bern Switzerland
| | - C. Sitaru
- Department of Dermatology and Centre for Biological Signaling Studies (BIOSS); University Medical Center Freiburg; Freiburg Germany
| | - M. Horn
- Centre of Laboratory Medicine; Inselspital; Bern University Hospital; Bern Switzerland
| | - L. Borradori
- Department of Dermatology; Inselspital; Bern University Hospital; University of Bern; Bern Switzerland
| | - S. Yousefi
- Institute of Pharmacology; University of Bern; Bern Switzerland
| | - H.-U. Simon
- Institute of Pharmacology; University of Bern; Bern Switzerland
| | - D. Simon
- Department of Dermatology; Inselspital; Bern University Hospital; University of Bern; Bern Switzerland
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25
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Diny NL, Rose NR, Čiháková D. Eosinophils in Autoimmune Diseases. Front Immunol 2017; 8:484. [PMID: 28496445 PMCID: PMC5406413 DOI: 10.3389/fimmu.2017.00484] [Citation(s) in RCA: 106] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 04/07/2017] [Indexed: 12/15/2022] Open
Abstract
Eosinophils are multifunctional granulocytes that contribute to initiation and modulation of inflammation. Their role in asthma and parasitic infections has long been recognized. Growing evidence now reveals a role for eosinophils in autoimmune diseases. In this review, we summarize the function of eosinophils in inflammatory bowel diseases, neuromyelitis optica, bullous pemphigoid, autoimmune myocarditis, primary biliary cirrhosis, eosinophilic granulomatosis with polyangiitis, and other autoimmune diseases. Clinical studies, eosinophil-targeted therapies, and experimental models have contributed to our understanding of the regulation and function of eosinophils in these diseases. By examining the role of eosinophils in autoimmune diseases of different organs, we can identify common pathogenic mechanisms. These include degranulation of cytotoxic granule proteins, induction of antibody-dependent cell-mediated cytotoxicity, release of proteases degrading extracellular matrix, immune modulation through cytokines, antigen presentation, and prothrombotic functions. The association of eosinophilic diseases with autoimmune diseases is also examined, showing a possible increase in autoimmune diseases in patients with eosinophilic esophagitis, hypereosinophilic syndrome, and non-allergic asthma. Finally, we summarize key future research needs.
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Affiliation(s)
- Nicola L Diny
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, USA
| | - Noel R Rose
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Daniela Čiháková
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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26
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Akuthota P, Carmo LAS, Bonjour K, Murphy RO, Silva TP, Gamalier JP, Capron KL, Tigges J, Toxavidis V, Camacho V, Ghiran I, Ueki S, Weller PF, Melo RCN. Extracellular Microvesicle Production by Human Eosinophils Activated by "Inflammatory" Stimuli. Front Cell Dev Biol 2016; 4:117. [PMID: 27833910 PMCID: PMC5081571 DOI: 10.3389/fcell.2016.00117] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 10/07/2016] [Indexed: 01/08/2023] Open
Abstract
A key function of human eosinophils is to secrete cytokines, chemokines and cationic proteins, trafficking, and releasing these mediators for roles in inflammation and other immune responses. Eosinophil activation leads to secretion of pre-synthesized granule-stored mediators through different mechanisms, but the ability of eosinophils to secrete extracellular vesicles (EVs), very small vesicles with preserved membrane topology, is still poorly understood. In the present work, we sought to identify and characterize EVs released from human eosinophils during different conditions: after a culturing period or after isolation and stimulation with inflammatory stimuli, which are known to induce eosinophil activation and secretion: CCL11 (eotaxin-1) and tumor necrosis factor alpha (TNF-α). EV production was investigated by nanoscale flow cytometry, conventional transmission electron microscopy (TEM) and pre-embedding immunonanogold EM. The tetraspanins CD63 and CD9 were used as EV biomarkers for both flow cytometry and ultrastructural immunolabeling. Nanoscale flow cytometry showed that human eosinophils produce EVs in culture and that a population of EVs expressed detectable CD9, while CD63 was not consistently detected. When eosinophils were stimulated immediately after isolation and analyzed by TEM, EVs were clearly identified as microvesicles (MVs) outwardly budding off the plasma membrane. Both CCL11 and TNF-α induced significant increases of MVs compared to unstimulated cells. TNF-α induced amplified release of MVs more than CCL11. Eosinophil MV diameters varied from 20 to 1000 nm. Immunonanogold EM revealed clear immunolabeling for CD63 and CD9 on eosinophil MVs, although not all MVs were labeled. Altogether, we identified, for the first time, that human eosinophils secrete MVs and that this production increases in response to inflammatory stimuli. This is important to understand the complex secretory activities of eosinophils underlying immune responses. The contribution of the eosinophil-derived MVs to the regulation of immune responses awaits further investigation.
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Affiliation(s)
- Praveen Akuthota
- Division of Allergy and Inflammation, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical SchoolBoston, MA, USA; Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of California San DiegoLa Jolla, CA, USA
| | - Lívia A S Carmo
- Laboratory of Cellular Biology, Department of Biology, Institute of Biological Sciences (ICB), Federal University of Juiz de Fora Juiz de Fora, Brazil
| | - Kennedy Bonjour
- Laboratory of Cellular Biology, Department of Biology, Institute of Biological Sciences (ICB), Federal University of Juiz de Fora Juiz de Fora, Brazil
| | - Ryann O Murphy
- Division of Allergy and Inflammation, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School Boston, MA, USA
| | - Thiago P Silva
- Laboratory of Cellular Biology, Department of Biology, Institute of Biological Sciences (ICB), Federal University of Juiz de Fora Juiz de Fora, Brazil
| | - Juliana P Gamalier
- Laboratory of Cellular Biology, Department of Biology, Institute of Biological Sciences (ICB), Federal University of Juiz de Fora Juiz de Fora, Brazil
| | - Kelsey L Capron
- Division of Allergy and Inflammation, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School Boston, MA, USA
| | - John Tigges
- Flow Cytometry Core, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School Boston, MA, USA
| | - Vasilis Toxavidis
- Flow Cytometry Core, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School Boston, MA, USA
| | - Virginia Camacho
- Flow Cytometry Core, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School Boston, MA, USA
| | - Ionita Ghiran
- Division of Allergy and Inflammation, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School Boston, MA, USA
| | - Shigeharu Ueki
- Department of General Internal Medicine and Clinical Laboratory Medicine, Akita University Graduate School of Medicine Akita, Japan
| | - Peter F Weller
- Division of Allergy and Inflammation, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School Boston, MA, USA
| | - Rossana C N Melo
- Division of Allergy and Inflammation, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical SchoolBoston, MA, USA; Laboratory of Cellular Biology, Department of Biology, Institute of Biological Sciences (ICB), Federal University of Juiz de ForaJuiz de Fora, Brazil
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27
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Melo RCN, Weller PF. Vesicular trafficking of immune mediators in human eosinophils revealed by immunoelectron microscopy. Exp Cell Res 2016; 347:385-90. [PMID: 27562864 DOI: 10.1016/j.yexcr.2016.08.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2016] [Revised: 08/19/2016] [Accepted: 08/20/2016] [Indexed: 01/21/2023]
Abstract
Electron microscopy (EM)-based techniques are mostly responsible for our current view of cell morphology at the subcellular level and continue to play an essential role in biological research. In cells from the immune system, such as eosinophils, EM has helped to understand how cells package and release mediators involved in immune responses. Ultrastructural investigations of human eosinophils enabled visualization of secretory processes in detail and identification of a robust, vesicular trafficking essential for the secretion of immune mediators via a non-classical secretory pathway associated with secretory (specific) granules. This vesicular system is mainly organized as large tubular-vesicular carriers (Eosinophil Sombrero Vesicles - EoSVs) actively formed in response to cell activation and provides a sophisticated structural mechanism for delivery of granule-stored mediators. In this review, we highlight the application of EM techniques to recognize pools of immune mediators at vesicular compartments and to understand the complex secretory pathway within human eosinophils involved in inflammatory and allergic responses.
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Affiliation(s)
- Rossana C N Melo
- Laboratory of Cellular Biology, Department of Biology, ICB, Federal University of Juiz de Fora, UFJF, Rua José Lourenço Kelmer, Juiz de Fora, MG 36036-900, Brazil; Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, CLS 943, Boston, MA 02215, USA.
| | - Peter F Weller
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, CLS 943, Boston, MA 02215, USA
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Carmo LAS, Bonjour K, Ueki S, Neves JS, Liu L, Spencer LA, Dvorak AM, Weller PF, Melo RCN. CD63 is tightly associated with intracellular, secretory events chaperoning piecemeal degranulation and compound exocytosis in human eosinophils. J Leukoc Biol 2016; 100:391-401. [PMID: 26965633 PMCID: PMC6608091 DOI: 10.1189/jlb.3a1015-480r] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 01/18/2016] [Accepted: 02/02/2016] [Indexed: 12/26/2022] Open
Abstract
Eosinophil activation leads to secretion of presynthesized, granule-stored mediators that determine the course of allergic, inflammatory, and immunoregulatory responses. CD63, a member of the transmembrane-4 glycoprotein superfamily (tetraspanins) and present on the limiting membranes of eosinophil-specific (secretory) granules, is considered a potential surface marker for eosinophil degranulation. However, the intracellular secretory trafficking of CD63 in eosinophils and other leukocytes is not understood. Here, we provide a comprehensive investigation of CD63 trafficking at high resolution within human eosinophils stimulated with inflammatory stimuli, CCL11 and tumor necrosis factor α, which induce distinctly differing secretory processes in eosinophils: piecemeal degranulation and compound exocytosis, respectively. By using different transmission electron microscopy approaches, including an immunonanogold technique, for enhanced detection of CD63 at subcellular compartments, we identified a major intracellular pool of CD63 that is directly linked to eosinophil degranulation events. Transmission electron microscopy quantitative analyses demonstrated that, in response to stimulation, CD63 is concentrated within granules undergoing secretion by piecemeal degranulation or compound exocytosis and that CD63 tracks with the movements of vesicles and granules in the cytoplasm. Although CD63 was observed at the cell surface after stimulation, immunonanogold electron microscopy revealed that a strong CD63 pool remains in the cytoplasm. It is remarkable that CCL11 and tumor necrosis factor α triggered increased formation of CD63(+) large vesiculotubular carriers (eosinophil sombrero vesicles), which fused with granules in the process of secretion, likely acting in the intracellular translocation of CD63. Altogether, we identified active, intracellular CD63 trafficking connected to eosinophil granule-derived secretory pathways. This is important for understanding the complex secretory activities of eosinophils underlying immune responses.
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Affiliation(s)
- Lívia A S Carmo
- Laboratory of Cellular Biology, Department of Biology, ICB, Federal University of Juiz de Fora, UFJF, Juiz de Fora, Brazil
| | - Kennedy Bonjour
- Laboratory of Cellular Biology, Department of Biology, ICB, Federal University of Juiz de Fora, UFJF, Juiz de Fora, Brazil
| | - Shigeharu Ueki
- Department of General Internal Medicine and Clinical Laboratory Medicine, Akita University Graduate School of Medicine, Akita, Japan
| | - Josiane S Neves
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Linying Liu
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA; and
| | - Lisa A Spencer
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA; and
| | - Ann M Dvorak
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Peter F Weller
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA; and
| | - Rossana C N Melo
- Laboratory of Cellular Biology, Department of Biology, ICB, Federal University of Juiz de Fora, UFJF, Juiz de Fora, Brazil; Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA; and
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29
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Melo RCN, Weller PF. Lipid droplets in leukocytes: Organelles linked to inflammatory responses. Exp Cell Res 2015; 340:193-7. [PMID: 26515551 DOI: 10.1016/j.yexcr.2015.10.028] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 10/23/2015] [Indexed: 01/21/2023]
Abstract
Studies on lipid droplets (LDs) in leukocytes have attracted attention due to their association with human diseases. In these cells, LDs are rapidly formed in response to inflammatory stimuli or allergic/inflammatory diseases including infections with parasites and bacteria. Leukocyte LDs are linked to the regulation of immune responses by compartmentalization of several proteins and lipids involved in the control and biosynthesis of inflammatory mediators (eicosanoids). In this mini review, we summarize current knowledge on the composition, structure and function of leukocyte LDs, organelles now considered as structural markers of inflammation.
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Affiliation(s)
- Rossana C N Melo
- Laboratory of Cellular Biology, Department of Biology, ICB, Federal University of Juiz de Fora, UFJF, Rua José Lourenço Kelmer, Juiz de Fora, MG 36036-900, Brazil; Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, CLS 943, Boston, MA 02215, USA.
| | - Peter F Weller
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, CLS 943, Boston, MA 02215, USA.
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30
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Expression and subcellular localization of the Qa-SNARE syntaxin17 in human eosinophils. Exp Cell Res 2015; 337:129-135. [PMID: 26254897 DOI: 10.1016/j.yexcr.2015.07.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2015] [Revised: 06/29/2015] [Accepted: 07/06/2015] [Indexed: 01/21/2023]
Abstract
BACKGROUND SNARE members mediate membrane fusion during intracellular trafficking underlying innate and adaptive immune responses by different cells. However, little is known about the expression and function of these proteins in human eosinophils, cells involved in allergic, inflammatory and immunoregulatory responses. Here, we investigate the expression and distribution of the Qa-SNARE syntaxin17 (STX17) within human eosinophils isolated from the peripheral blood. METHODS Flow cytometry and a pre-embedding immunonanogold electron microscopy (EM) technique that combines optimal epitope preservation and secondary Fab-fragments of antibodies linked to 1.4 nm gold particles for optimal access to microdomains, were used to investigate STX17. RESULTS STX17 was detected within unstimulated eosinophils. Immunogold EM revealed STX17 on secretory granules and on granule-derived vesiculotubular transport carriers (Eosinophil Sombrero Vesicles-EoSVs). Quantitative EM analyses showed that 77.7% of the granules were positive for STX17 with a mean±SEM of 3.9±0.2 gold particles/granule. Labeling was present on both granule outer membranes and matrices while EoSVs showed clear membrane-associated labeling. STX17 was also present in secretory granules in eosinophils stimulated with the cytokine tumor necrosis factor alpha (TNF-α) or the CC-chemokine ligand 11 CCL11 (eotaxin-1), stimuli that induce eosinophil degranulation. The number of secretory granules labeled for STX17 was significantly higher in CCL11 compared with the unstimulated group. The level of cell labeling did not change when unstimulated cells were compared with TNF-α-stimulated eosinophils. CONCLUSIONS The present study clearly shows by immunanonogold EM that STX17 is localized in eosinophil secretory granules and transport vesicles and might be involved in the transport of granule-derived cargos.
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31
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Davoine F, Lacy P. Eosinophil cytokines, chemokines, and growth factors: emerging roles in immunity. Front Immunol 2014; 5:570. [PMID: 25426119 PMCID: PMC4225839 DOI: 10.3389/fimmu.2014.00570] [Citation(s) in RCA: 193] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Accepted: 10/24/2014] [Indexed: 12/30/2022] Open
Abstract
Eosinophils derive from the bone marrow and circulate at low levels in the blood in healthy individuals. These granulated cells preferentially leave the circulation and marginate to tissues, where they are implicated in the regulation of innate and adaptive immunity. In diseases such as allergic inflammation, eosinophil numbers escalate markedly in the blood and tissues where inflammatory foci are located. Eosinophils possess a range of immunomodulatory factors that are released upon cell activation, including over 35 cytokines, growth factors, and chemokines. Unlike T and B cells, eosinophils can rapidly release cytokines within minutes in response to stimulation. While some cytokines are stored as pre-formed mediators in crystalloid granules and secretory vesicles, eosinophils are also capable of undergoing de novo synthesis and secretion of these immunological factors. Some of the molecular mechanisms that coordinate the final steps of cytokine secretion are hypothesized to involve binding of membrane fusion complexes comprised of soluble N-ethylmaleimide sensitive factor attachment protein receptors (SNAREs). These intracellular receptors regulate the release of granules and vesicles containing a range of secreted proteins, among which are cytokines and chemokines. Emerging evidence from both human and animal model-based research has suggested an active participation of eosinophils in several physiological/pathological processes such as immunomodulation and tissue remodeling. The observed eosinophil effector functions in health and disease implicate eosinophil cytokine secretion as a fundamental immunoregulatory process. The focus of this review is to describe the cytokines, growth factors, and chemokines that are elaborated by eosinophils, and to illustrate some of the intracellular events leading to the release of eosinophil-derived cytokines.
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Affiliation(s)
- Francis Davoine
- Pulmonary Research Group, Department of Medicine, University of Alberta , Edmonton, AB , Canada
| | - Paige Lacy
- Pulmonary Research Group, Department of Medicine, University of Alberta , Edmonton, AB , Canada
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32
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Spencer LA, Bonjour K, Melo RCN, Weller PF. Eosinophil secretion of granule-derived cytokines. Front Immunol 2014; 5:496. [PMID: 25386174 PMCID: PMC4209865 DOI: 10.3389/fimmu.2014.00496] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Accepted: 09/23/2014] [Indexed: 12/30/2022] Open
Abstract
Eosinophils are tissue-dwelling leukocytes, present in the thymus, and gastrointestinal and genitourinary tracts of healthy individuals at baseline, and recruited, often in large numbers, to allergic inflammatory foci and sites of active tissue repair. The biological significance of eosinophils is vast and varied. In health, eosinophils support uterine and mammary gland development, and maintain bone marrow plasma cells and adipose tissue alternatively activated macrophages, while in response to tissue insult eosinophils function as inflammatory effector cells, and, in the wake of an inflammatory response, promote tissue regeneration, and wound healing. One common mechanism driving many of the diverse eosinophil functions is the regulated and differential secretion of a vast array of eosinophil-derived cytokines. Eosinophils are distinguished from most other leukocytes in that many, if not all, of the over three dozen eosinophil-derived cytokines are pre-synthesized and stored within intracellular granules, poised for very rapid, stimulus-induced secretion. Eosinophils engaged in cytokine secretion in situ utilize distinct pathways of cytokine release that include classical exocytosis, whereby granules themselves fuse with the plasma membrane and release their entire contents extracellularly; piecemeal degranulation, whereby granule-derived cytokines are selectively mobilized into vesicles that emerge from granules, traverse the cytoplasm and fuse with the plasma membrane to release discrete packets of cytokines; and eosinophil cytolysis, whereby intact granules are extruded from eosinophils, and deposited within tissues. In this latter scenario, extracellular granules can themselves function as stimulus-responsive secretory-competent organelles within the tissue. Here, we review the distinctive processes of differential secretion of eosinophil granule-derived cytokines.
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Affiliation(s)
- Lisa A Spencer
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School , Boston, MA , USA
| | - Kennedy Bonjour
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora (UFJF) , Juiz de Fora , Brazil
| | - Rossana C N Melo
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora (UFJF) , Juiz de Fora , Brazil
| | - Peter F Weller
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School , Boston, MA , USA
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Melo RCN, Morgan E, Monahan-Earley R, Dvorak AM, Weller PF. Pre-embedding immunogold labeling to optimize protein localization at subcellular compartments and membrane microdomains of leukocytes. Nat Protoc 2014; 9:2382-94. [PMID: 25211515 DOI: 10.1038/nprot.2014.163] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Precise immunolocalization of proteins within a cell is central to understanding cell processes and functions such as intracellular trafficking and secretion of molecules during immune responses. Here we describe a protocol for ultrastructural detection of proteins in leukocytes. The method uses a pre-embedding approach (immunolabeling before standard processing for transmission electron microscopy (TEM)). This protocol combines several strategies for ultrastructure and antigen preservation, robust blocking of nonspecific binding sites, as well as superior antibody penetration for detecting molecules at subcellular compartments and membrane microdomains. A further advantage of this technique is that electron microscopy (EM) processing is quick. This method has been used to study leukocyte biology, and it has helped demonstrate how activated leukocytes deliver specific cargos. It may also potentially be applied to a variety of different cell types. Excluding the initial time required for sample preparation (15 h) and the final resin polymerization step (16 h), the protocol (immunolabeling and EM procedures) can be completed in 8 h.
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Affiliation(s)
- Rossana C N Melo
- 1] Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora, Juiz de Fora, Minas Gerais, Brazil. [2] Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Ellen Morgan
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Rita Monahan-Earley
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Ann M Dvorak
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Peter F Weller
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
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Melo RCN, Weller PF. Unraveling the complexity of lipid body organelles in human eosinophils. J Leukoc Biol 2014; 96:703-12. [PMID: 25210147 DOI: 10.1189/jlb.3ru0214-110r] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Lipid-rich organelles are common in many cell types. In cells, such as adipocytes, these organelles are termed LDs, whereas in other cells, such as leukocytes, they are called LBs. The study of leukocyte LBs has attracted attention as a result of their association with human diseases. In leukocytes, such as eosinophils, LB accumulation has been documented extensively during inflammatory conditions. In these cells, LBs are linked to the regulation of immune responses by compartmentalization of several proteins and lipids involved in the control and biosynthesis of inflammatory mediators (eicosanoids). However, it has been unclear how diverse proteins, including membrane-associated enzymes involved in eicosanoid formation, incorporate into LBs, especially if the internal content of LBs is assumed to consist solely of stores of neutral lipids, as present within adipocyte LDs. Studies of the formation, function, and ultrastructure of LBs in eosinophils have been providing insights pertinent to LBs in other leukocytes. Here, we review current knowledge of the composition and function of leukocyte LBs as provided by studies of human eosinophil LBs, including recognitions of the internal architecture of eosinophil LBs based on 3D electron tomographic analyses.
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Affiliation(s)
- Rossana C N Melo
- Laboratory of Cellular Biology, Department of Biology, Institute of Biological Sciences, Federal University of Juiz de Fora, Brazil; and Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Peter F Weller
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
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35
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Abstract
Eosinophils are multifunctional granular leukocytes that are implicated in the pathogenesis of a wide variety of disorders, including asthma, helminth infection, and rare hypereosinophilic syndromes. Although peripheral and tissue eosinophilia can be a feature of many types of small-vessel and medium-vessel vasculitis, the role of eosinophils has been best studied in eosinophilic granulomatosis with polyangiitis (EGPA), where eosinophils are a characteristic finding in all three clinical stages of the disorder. Whereas numerous studies have demonstrated an association between the presence of eosinophils and markers of eosinophil activation in the blood and tissues of patients with EGPA, the precise role of eosinophils in disease pathogenesis has been difficult to ascertain owing to the complexity of the disease process. In this regard, results of clinical trials using novel agents that specifically target eosinophils are providing the first direct evidence of a central role of eosinophils in EGPA. This Review focuses on the aspects of eosinophil biology most relevant to the pathogenesis of vasculitis and provides an update of current knowledge regarding the role of eosinophils in EGPA and other vasculitides.
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Abstract
In this issue of Blood, Percopo et al provide intriguing new evidence supporting a role for eosinophils in protecting mice against the lethal effects of respiratory virus infection.
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37
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Dias FF, Amaral KB, Carmo LAS, Shamri R, Dvorak AM, Weller PF, Melo RCN. Human Eosinophil Leukocytes Express Protein Disulfide Isomerase in Secretory Granules and Vesicles: Ultrastructural Studies. J Histochem Cytochem 2014; 62:450-459. [PMID: 24670795 DOI: 10.1369/0022155414531437] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Protein disulfide isomerase (PDI) has fundamental roles in the oxidative folding of proteins in the endoplasmic reticulum (ER) of eukaryotic cells. The study of this molecule has been attracting considerable attention due to its association with other cell functions and human diseases. In leukocytes, such as neutrophils, PDI is involved with cell adhesion, signaling and inflammation. However, the expression of PDI in other leukocytes, such as eosinophils, important cells in inflammatory, allergic and immunomodulatory responses, remains to be defined. Here we used different approaches to investigate PDI expression within human eosinophils. Western blotting and flow cytometry demonstrated high PDI expression in both unstimulated and CCL11/eotaxin-1-stimulated eosinophils, with similar levels in both conditions. By using an immunogold electron microscopy technique that combines better epitope preservation and secondary Fab-fragments of antibodies linked to 1.4-nm gold particles for optimal access to microdomains, we identified different intracellular sites for PDI. In addition to predictable strong PDI labeling at the nuclear envelope, other unanticipated sites, such as secretory granules, lipid bodies and vesicles, including large transport vesicles (eosinophil sombrero vesicles), were also labeled. Thus, we provide the first identification of PDI in human eosinophils, suggesting that this molecule may have additional/specific functions in these leukocytes.
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Affiliation(s)
- Felipe F Dias
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora, UFJF, Juiz de Fora, MG, Brazil (FFD,KBA,LASC,RCNM)Department of Pathology (AMD)Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts (RS,PFW,RCNM)
| | - Kátia B Amaral
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora, UFJF, Juiz de Fora, MG, Brazil (FFD,KBA,LASC,RCNM)Department of Pathology (AMD)Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts (RS,PFW,RCNM)
| | - Lívia A S Carmo
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora, UFJF, Juiz de Fora, MG, Brazil (FFD,KBA,LASC,RCNM)Department of Pathology (AMD)Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts (RS,PFW,RCNM)
| | - Revital Shamri
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora, UFJF, Juiz de Fora, MG, Brazil (FFD,KBA,LASC,RCNM)Department of Pathology (AMD)Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts (RS,PFW,RCNM)
| | - Ann M Dvorak
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora, UFJF, Juiz de Fora, MG, Brazil (FFD,KBA,LASC,RCNM)Department of Pathology (AMD)Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts (RS,PFW,RCNM)
| | - Peter F Weller
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora, UFJF, Juiz de Fora, MG, Brazil (FFD,KBA,LASC,RCNM)Department of Pathology (AMD)Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts (RS,PFW,RCNM)
| | - Rossana C N Melo
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora, UFJF, Juiz de Fora, MG, Brazil (FFD,KBA,LASC,RCNM)Department of Pathology (AMD)Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts (RS,PFW,RCNM)
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38
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Rosenberg HF, Foster PS. Reply to eosinophil cytolysis and release of cell-free granules. Nat Rev Immunol 2014; 13:902. [PMID: 24270783 DOI: 10.1038/nri3341-c2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Helene F Rosenberg
- Inflammation Immunobiology Section, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
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39
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An extragranular compartment of blood eosinophils contains eosinophil protein X/eosinophil-derived neurotoxin (EPX/EDN). Inflammation 2013; 36:320-9. [PMID: 23053729 DOI: 10.1007/s10753-012-9549-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Serum and plasma profiles of eosinophil protein X (EPX/EDN) and those of other eosinophil proteins differ in various conditions, suggesting a different mobilisation from storage granules. This work studied the subcellular localisation of EPX/EDN in non-primed and in vivo primed blood eosinophils from healthy and allergic subjects, during and out of the pollen season. Primed eosinophils contain easily mobilisable secretory proteins. By fractionation on sucrose density gradients, EPX/EDN localised in the specific granules as well as in a cytoplasmic extra-granular compartment of low equilibrium density that partially overlapped with vesicular structures, cytosolic proteins and plasma membranes. This compartment was clearly separate from the low density peak of ECP that increases during the pollen season. There were no significant differences in the amounts of EPX/EDN present in the low density peak of healthy and allergic subjects. Immuno-gold labelling electron microscopy showed EPX/EDN in specific granules, cytoplasm and associated to plasma membranes. In conclusion, substantial amounts of EPX/EDN localise in an extra-granular, low equilibrium density compartment of human eosinophils.
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40
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Stow JL, Murray RZ. Intracellular trafficking and secretion of inflammatory cytokines. Cytokine Growth Factor Rev 2013; 24:227-39. [PMID: 23647915 DOI: 10.1016/j.cytogfr.2013.04.001] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The secretion of cytokines by immune cells plays a significant role in determining the course of an inflammatory response. The levels and timing of each cytokine released are critical for mounting an effective but confined response, whereas excessive or dysregulated inflammation contributes to many diseases. Cytokines are both culprits and targets for effective treatments in some diseases. The multiple points and mechanisms that have evolved for cellular control of cytokine secretion highlight the potency of these mediators and the fine tuning required to manage inflammation. Cytokine production in cells is regulated by cell signaling, and at mRNA and protein synthesis levels. Thereafter, the intracellular transport pathways and molecular trafficking machinery have intricate and essential roles in dictating the release and activity of cytokines. The trafficking machinery and secretory (exocytic) pathways are complex and highly regulated in many cells, involving specialized membranes, molecules and organelles that enable these cells to deliver cytokines to often-distinct areas of the cell surface, in a timely manner. This review provides an overview of secretory pathways - both conventional and unconventional - and key families of trafficking machinery. The prevailing knowledge about the trafficking and secretion of a number of individual cytokines is also summarized. In conclusion, we present emerging concepts about the functional plasticity of secretory pathways and their modulation for controlling cytokines and inflammation.
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Affiliation(s)
- Jennifer L Stow
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia.
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41
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Melo RCN, Paganoti GF, Dvorak AM, Weller PF. The internal architecture of leukocyte lipid body organelles captured by three-dimensional electron microscopy tomography. PLoS One 2013; 8:e59578. [PMID: 23555714 PMCID: PMC3608657 DOI: 10.1371/journal.pone.0059578] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Accepted: 02/15/2013] [Indexed: 01/04/2023] Open
Abstract
Lipid bodies (LBs), also known as lipid droplets, are complex organelles of all eukaryotic cells linked to a variety of biological functions as well as to the development of human diseases. In cells from the immune system, such as eosinophils, neutrophils and macrophages, LBs are rapidly formed in the cytoplasm in response to inflammatory and infectious diseases and are sites of synthesis of eicosanoid lipid mediators. However, little is known about the structural organization of these organelles. It is unclear whether leukocyte LBs contain a hydrophobic core of neutral lipids as found in lipid droplets from adipocytes and how diverse proteins, including enzymes involved in eicosanoid formation, incorporate into LBs. Here, leukocyte LB ultrastructure was studied in detail by conventional transmission electron microscopy (TEM), immunogold EM and electron tomography. By careful analysis of the two-dimensional ultrastructure of LBs from human blood eosinophils under different conditions, we identified membranous structures within LBs in both resting and activated cells. Cyclooxygenase, a membrane inserted protein that catalyzes the first step in prostaglandin synthesis, was localized throughout the internum of LBs. We used fully automated dual-axis electron tomography to study the three-dimensional architecture of LBs in high resolution. By tracking 4 nm-thick serial digital sections we found that leukocyte LBs enclose an intricate system of membranes within their “cores”. After computational reconstruction, we showed that these membranes are organized as a network of tubules which resemble the endoplasmic reticulum (ER). Our findings explain how membrane-bound proteins interact and are spatially arranged within LB “cores” and support a model for LB formation by incorporating cytoplasmic membranes of the ER, instead of the conventional view that LBs emerge from the ER leaflets. This is important to understand the functional capabilities of leukocyte LBs in health and during diverse diseases in which these organelles are functionally involved.
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Affiliation(s)
- Rossana C. N. Melo
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora, UFJF, Juiz de Fora, MG, Brazil
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Guillherme F. Paganoti
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora, UFJF, Juiz de Fora, MG, Brazil
| | - Ann M. Dvorak
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Peter F. Weller
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
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42
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Melo RCN, Liu L, Xenakis JJ, Spencer LA. Eosinophil-derived cytokines in health and disease: unraveling novel mechanisms of selective secretion. Allergy 2013; 68:274-84. [PMID: 23347072 DOI: 10.1111/all.12103] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/30/2012] [Indexed: 12/13/2022]
Abstract
Over the past two decades, our understanding of eosinophils has evolved from that of categorically destructive effector cells to include active participation in immune modulation, tissue repair processes, and normal organ development, in both health and disease. At the core of their newly appreciated functions is the capacity of eosinophils to synthesize, store within intracellular granules, and very rapidly secrete a highly diverse repertoire of cytokines. Mechanisms governing the selective secretion of preformed cytokines from eosinophils are attractive therapeutic targets and may well be more broadly applicable to other immune cells. Here, we discuss recent advances in deciphering pathways of cytokine secretion, both from intact eosinophils and from tissue-deposited cell-free eosinophil granules, extruded from eosinophils undergoing a lytic cell death.
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Affiliation(s)
| | - L. Liu
- Division of Allergy and Inflammation; Department of Medicine; Beth Israel Deaconess Medical Center; Harvard Medical School; Boston; MA; USA
| | - J. J. Xenakis
- Division of Allergy and Inflammation; Department of Medicine; Beth Israel Deaconess Medical Center; Harvard Medical School; Boston; MA; USA
| | - L. A. Spencer
- Division of Allergy and Inflammation; Department of Medicine; Beth Israel Deaconess Medical Center; Harvard Medical School; Boston; MA; USA
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43
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Muniz VS, Weller PF, Neves JS. Eosinophil crystalloid granules: structure, function, and beyond. J Leukoc Biol 2012; 92:281-8. [PMID: 22672875 DOI: 10.1189/jlb.0212067] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Eosinophils are granulocytes associated with host defense against parasitic helminths with allergic conditions and more recently, with immunoregulatory responses. Eosinophils are distinguished from leukocytes by their dominant population of cytoplasmic crystalloid (also termed secretory, specific, or secondary) granules that contain robust stores of diverse, preformed cationic proteins. Here, we provide an update on our knowledge about the unique and complex structure of human eosinophil crystalloid granules. We discuss their significance as rich sites of a variety of receptors and review our own recent research findings and those of others that highlight discoveries concerning the function of intracellular receptors and their potential implications in cell signaling. Special focus is provided on how eosinophils might use these intracellular receptors as mechanisms to secrete, selectively and rapidly, cytokines or chemokines and enable cell-free extracellular eosinophil granules to function as independent secretory structures. Potential roles of cell-free eosinophil granules as immune players in the absence of intact eosinophils will also be discussed.
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Affiliation(s)
- Valdirene S Muniz
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, UFRJ, Rio de Janeiro, Brazil
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44
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Shamri R, Melo RCN, Young KM, Bivas-Benita M, Xenakis JJ, Spencer LA, Weller PF. CCL11 elicits secretion of RNases from mouse eosinophils and their cell-free granules. FASEB J 2012; 26:2084-93. [PMID: 22294786 DOI: 10.1096/fj.11-200246] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Rapid secretion of eosinophil-associated RNases (EARs), such as the human eosinophilic cationic protein (ECP), from intracellular granules is central to the role of eosinophils in allergic diseases and host immunity. Our knowledge regarding allergic inflammation has advanced based on mouse experimental models. However, unlike human eosinophils, capacities of mouse eosinophils to secrete granule proteins have been controversial. To study mechanisms of mouse eosinophil secretion and EAR release, we combined an RNase assay of mouse EARs with ultrastructural studies. In vitro, mouse eosinophils stimulated with the chemokine eotaxin-1 (CCL11) secreted enzymatically active EARs (EC(50) 5 nM) by piecemeal degranulation. In vivo, in a mouse model of allergic airway inflammation, increased airway eosinophil infiltration (24-fold) correlated with secretion of active RNases (3-fold). Moreover, we found that eosinophilic inflammation in mice can involve eosinophil cytolysis and release of cell-free granules. Cell-free mouse eosinophil granules expressed functional CCR3 receptors and secreted their granule proteins, including EAR and eosinophil peroxidase in response to CCL11. Collectively, these data demonstrate chemokine-dependent secretion of EARs from both intact mouse eosinophils and their cell-free granules, findings pertinent to understanding the pathogenesis of eosinophil-associated diseases, in which EARs are key factors.
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Affiliation(s)
- Revital Shamri
- Division of Allergy and Inflammation, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
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45
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Verjan Garcia N, Umemoto E, Saito Y, Yamasaki M, Hata E, Matozaki T, Murakami M, Jung YJ, Woo SY, Seoh JY, Jang MH, Aozasa K, Miyasaka M. SIRPα/CD172a regulates eosinophil homeostasis. THE JOURNAL OF IMMUNOLOGY 2011; 187:2268-77. [PMID: 21775684 DOI: 10.4049/jimmunol.1101008] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Eosinophils are abundant in the lamina propria of the small intestine, but they rarely show degranulation in situ under steady-state conditions. In this study, using two novel mAbs, we found that intestinal eosinophils constitutively expressed a high level of an inhibitory receptor signal regulatory protein α (SIRPα)/CD172a and a low, but significant, level of a tetraspanin CD63, whose upregulation is closely associated with degranulation. Cross-linking SIRPα/CD172a on the surface of wild-type eosinophils significantly inhibited the release of eosinophil peroxidase induced by the calcium ionophore A23187, whereas this cross-linking effect was not observed in eosinophils isolated from mice expressing a mutated SIRPα/CD172a that lacks most of its cytoplasmic domain (SIRPα Cyto(-/-)). The SIRPα Cyto(-/-) eosinophils showed reduced viability, increased CD63 expression, and increased eosinophil peroxidase release with or without A23187 stimulation in vitro. In addition, SIRPα Cyto(-/-) mice showed increased frequencies of Annexin V-binding eosinophils and free MBP(+)CD63(+) extracellular granules, as well as increased tissue remodeling in the small intestine under steady-state conditions. Mice deficient in CD47, which is a ligand for SIRPα/CD172a, recapitulated these phenomena. Moreover, during Th2-biased inflammation, increased eosinophil cell death and degranulation were obvious in a number of tissues, including the small intestine, in the SIRPα Cyto(-/-) mice compared with wild-type mice. Collectively, our results indicated that SIRPα/CD172a regulates eosinophil homeostasis, probably by interacting with CD47, with substantial effects on eosinophil survival. Thus, SIRPα/CD172a is a potential therapeutic target for eosinophil-associated diseases.
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Affiliation(s)
- Noel Verjan Garcia
- Laboratory of Immunodynamics, World Premier International Immunology Frontier Research Center, Osaka University, Osaka 565-0871, Japan
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46
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Cytokine release from innate immune cells: association with diverse membrane trafficking pathways. Blood 2011; 118:9-18. [PMID: 21562044 DOI: 10.1182/blood-2010-08-265892] [Citation(s) in RCA: 252] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Cytokines released from innate immune cells play key roles in the regulation of the immune response. These intercellular messengers are the source of soluble regulatory signals that initiate and constrain inflammatory responses to pathogens and injury. Although numerous studies describe detailed signaling pathways induced by cytokines and their specific receptors, there is little information on the mechanisms that control the release of cytokines from different cell types. Indeed, the pathways, molecules, and mechanisms of cytokine release remain a "black box" in immunology. Here, we review research findings and new approaches that have begun to generate information on cytokine trafficking and release by innate immune cells in response to inflammatory or infectious stimuli. Surprisingly complex machinery, multiple organelles, and specialized membrane domains exist in these cells to ensure the selective, temporal, and often polarized release of cytokines in innate immunity.
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47
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Melo RCN, D'Ávila H, Bozza PT, Weller PF. Imaging lipid bodies within leukocytes with different light microscopy techniques. Methods Mol Biol 2011; 689:149-61. [PMID: 21153791 DOI: 10.1007/978-1-60761-950-5_9] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Lipid bodies, also known as lipid droplets, are present in most eukaryotic cells. In leukocytes, lipid bodies are functionally active organelles with central roles in inflammation and are considered structural markers of inflammatory cells in a range of diseases. The identification of lipid bodies has methodological limitations because lipid bodies dissipate upon drying or dissolve upon fixation and staining with alcohol-based reagents. Here we discuss several techniques to detect and visualize lipid bodies within leukocytes by light microscopy. These techniques include staining with osmium or use of different fluorescent probes such as Nile red, BODIPY, Oil red, P96 and immunofluorescence labeling for adipose differentiation-related protein (ADRP).
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Affiliation(s)
- Rossana C N Melo
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora, Juiz de Fora, MG, Brazil.
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48
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Melo RCN, Dvorak AM, Weller PF. Contributions of electron microscopy to understand secretion of immune mediators by human eosinophils. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2010; 16:653-60. [PMID: 20875166 PMCID: PMC3420811 DOI: 10.1017/s1431927610093864] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Mechanisms governing secretion of proteins underlie the biologic activities and functions of human eosinophils, leukocytes of the innate immune system, involved in allergic, inflammatory, and immunoregulatory responses. In response to varied stimuli, eosinophils are recruited from the circulation into inflammatory foci, where they modulate immune responses through the release of granule-derived products. Transmission electron microscopy (TEM) is the only technique that can clearly identify and distinguish between different modes of cell secretion. In this review, we highlight the advances in understanding mechanisms of eosinophil secretion, based on TEM findings, that have been made over the past years and that have provided unprecedented insights into the functional capabilities of these cells.
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Affiliation(s)
- Rossana C N Melo
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora, UFJF, Juiz de Fora, MG, Brazil.
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49
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Crivellato E, Nico B, Gallo VP, Ribatti D. Cell secretion mediated by granule-associated vesicle transport: a glimpse at evolution. Anat Rec (Hoboken) 2010; 293:1115-24. [PMID: 20340095 DOI: 10.1002/ar.21146] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Regulated secretion allows extrusion of cell products stored in specialized membrane-bound organelles called secretory granules or secretory vesicles. Regulated secretion provides basic functions in living organisms, and in a phylogenetic perspective, it is recognizable in the most primitive eukaryotic forms. This article is an attempt to trace the evolutionary history of a special type of secretory pattern, which has been referred to as vesicle-mediated degranulation or piecemeal degranulation (PMD). First described in the early 70s of the last century in inflammatory cells, such as the basophils, mast cells, and eosinophils, this regulated secretory route has subsequently been recognized in endocrine cells, in particular in the chromaffin cells of the adrenal medulla. This vesicle-mediated degranulation is held to mobilize small and specific aliquots of granule-associated material for selective paracrine or endocrine transport to the cell exterior. PMD has been identified in many vertebrate classes. By contrast, no data are available for invertebrates. We speculate that this pattern of cell secretion emerged early in phylogenesis, when the first metazoans appeared. In this review article, we will first revise the concept of vesicle-mediated degranulation in the light of the most recent experimental discoveries and theoretical implications. Then, the distribution of this secretory mode among vertebrates and its molecular basis will be highlighted. Finally, the potential occurrence of PMD in invertebrates, its biological significance from an evolutionary perspective and the future direction of investigations will be briefly sketched.
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Affiliation(s)
- Enrico Crivellato
- Department of Medical and Morphological Research, Section of Anatomy, University of Udine School of Medicine, Udine, Italy.
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50
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Melo RC, Weller PF. Piecemeal degranulation in human eosinophils: a distinct secretion mechanism underlying inflammatory responses. Histol Histopathol 2010; 25:1341-54. [PMID: 20712018 PMCID: PMC3427618 DOI: 10.14670/hh-25.1341] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Secretion is a fundamental cell process underlying different physiological and pathological events. In cells from the human immune system such as eosinophils, secretion of mediators generally occurs by means of piecemeal degranulation, an unconventional secretory pathway characterized by vesicular transport of small packets of materials from the cytoplasmic secretory granules to the cell surface. During piecemeal degranulation in eosinophils, a distinct transport vesicle system, which includes large, pleiomorphic vesiculo-tubular carriers is mobilized and enables regulated release of granule-stored proteins such as cytokines and major basic protein. Piecemeal degranulation underlies distinct functions of eosinophils as effector and immunoregulatory cells. This review focuses on the structural and functional advances that have been made over the last years concerning the intracellular trafficking and secretion of eosinophil proteins by piecemeal degranulation during inflammatory responses.
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Affiliation(s)
- Rossana C.N. Melo
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora, UFJF, Juiz de Fora, MG, Brazil
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Peter F. Weller
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
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